Oxynitride phosphor and production process thereof, and light-emitting device using oxynitride phosphor

ABSTRACT

An oxynitride phosphor consisting of a crystal containing at least one or more of Group II elements selected from the group consisting of Be, Mg, Ca, Sr, Ba and Zn, at least one or more of Group IV elements selected from the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf, and a rare earth element being an activator R, thereby providing a phosphor which is excited by an excitation light source at an ultraviolet to visible light region and which has a blue green to yellow luminescence color that is wavelength converted.

This application is a divisional application of U.S. application Ser.No. 10/531,085, filed Apr. 11, 2005, now U.S. Pat. No. 7,794,624, whichis the U.S. national phase of international applicationPCT/JP2003/013157, filed Oct. 15, 2003, which designated the U.S. andclaims benefit of JP 2002-301636; JP 2002-301637; JP 2002-381025; JP2003-28610; JP 2003-28611; JP 2003-70043, dated Oct. 16, 2002; Oct. 16,2002; Dec. 27, 2002; Feb. 5, 2003; Feb. 5, 2003; and Mar. 14, 2003, theentire content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a phosphor which emit a light by beingexcited by light, electromagnetic waves such as X-rays, electron beam,and specifically, relates to a light-emitting device for usualilluminations such as a fluorescent lamp, illuminations mounted on acar, backlights for liquid crystal, displays and the like. Specifically,the present invention relates to a white color and multi-colorlight-emitting device using a semiconductor light-emitting element.

2. Description of the Related Art

A light-emitting device using light-emitting elements is a small sizeand superior in electric power efficiency, and emits fresh color.Further, said light-emitting elements have characteristics that there isno fear of a burnt-out light bulb because of a semiconductor element andthey are superior in initial drive property and resistant in vibrationand the repetition of on-off lighting. Since the light-emitting elementshave such superior characteristics, alight-emitting device usingsemiconductor light-emitting elements such as an LED and a LD has beenutilized as various light sources.

There is developed a light-emitting device which emits a luminescencecolor different from the light of the light-emitting elements bypartially or wholly converting the wavelength of the light of thelight-emitting elements and mixing said wavelength-converted light withthe light of light-emitting elements not subjected to wavelengthconversion to release light.

Among these light-emitting devices, a white color light-emitting devicehas been required in wide fields such as usual illuminations such as aphosphorescent lamp, illuminations mounted on a car, displays and backlights for liquid crystal. Further, there is required a light-emittingdevice having various color tastes such as a pastel color by combining asemiconductor light-emitting element and a phosphor.

The luminescence color of a light-emitting device using a white colorsemiconductor light-emitting element is obtained by the theory of colormixture. Blue light released from a light-emitting element is irradiatedin a phosphor layer, then repeats absorption and scattering severaltimes in the layer, and then, is released to outside. On the other hand,the blue light absorbed in the phosphor works as an excitation lightsource and emits yellow fluorescent light. The mixture of the yellowlight and the blue light is visualized as white to human eyes.

For example, a blue color light-emitting element is used as thelight-emitting element, and a phosphor is thinly coated on the surfaceof said blue color light-emitting element. Said light-emitting elementis a blue color light-emitting device using an InGaN-base material.Further, the phosphor uses a YAG-base phosphor represented by thecomposition formula of (Y, Gd)₃(Al, Ga)₅O₁₂:Ce.

However, a white color light-emitting device equipped with the bluecolor light-emitting element and the YAG-base phosphor emits white colorlight formed by the color mixture of blue light nearby 460 nm and yellowgreen light nearby 565 nm, but luminescence intensity nearby 500 nm isinsufficient.

Further, there has been recently reported a white color light-emittingdevice combining a phosphor which emits blue light and a YAG-basephosphor which emits yellow light using light-emitting elements ofvisible light at a short wavelength side region. In this case, theYAG-base phosphor which emits yellow light is hardly excited by light ofvisible light at the short wavelength side region and does not emitlight. Accordingly, a blue color-base phosphor is excited by saidlight-emitting element to emit blue light. Then, the YAG-base phosphoris excited by said blue light to emit yellow light. Thus, white colorlight is emitted by the color mixture of the blue light of the bluecolor-base phosphor with the yellow light of the YAG-base phosphor.

Various phosphors are developed as the phosphor used in saidlight-emitting device.

For example, an oxide-base phosphor using a rare earth metal element fora luminescence center has been widely known, and a portion of thephosphor is already practically used. However, a nitride phosphor and anoxynitride phosphor are seldom studied, and a study report is scarcelyreported. For example, there is an oxynitride glass phosphor which isrepresented by Si—O—N, Mg—Si—O—N, Ca—Al—Si—O—N and the like(JP-A-2001-214162: hereinafter, referred to as the patent literature 1).Further, there is an oxynitride glass phosphor represented byCa—Al—Si—O—N in which Eu was activated (JP-A-2002-76434: hereinafter,referred to as the patent literature 2).

However, conventional phosphors have low luminescence brightness and areinsufficient for being used for a light-emitting device. In alight-emitting device using light-emitting elements at a nearultraviolet region as an excitation light source, there is used doublestep excitation that a blue light-base phosphor is excited by saidlight-emitting elements and the YAG-base phosphor is excited by saidexcited light, therefore while light having high efficiency is hardlyobtained. Accordingly, there is desired a phosphor emitting green lightto yellow light whose wavelength was directly converted by light ofvisible light at a short wavelength side region.

Further, a white color light-emitting device combining a phosphor and alight-emitting element of visible light at a short wavelength sideregion is not produced yet and the light-emitting device practicallyused is not commercially available. Accordingly, a phosphor whichefficiently emits light at a short wavelength side region of visiblelight is desired.

Further, the above-mentioned oxynitride phosphors and the like describedin the patent literatures 1 and 2 have low luminescence brightness andare insufficient for being used for the light-emitting device. Further,since the oxynitride glass phosphor is a glass body, it is hardlyprocessed in general.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a phosphorwhich is excited by an excitation light source at an ultraviolet tovisible light region and which has a blue green to yellow luminescencecolor that is wavelength converted, and to provide a light-emittingdevice using thereof. Further, the purpose of the present invention isto provide a light-emitting device having high luminescence efficiencyand being superior in reproducibility.

Further, the purpose of the present invention is to provide a phosphorin which the color tone is easily adjusted and to provide alight-emitting device using thereof.

In order to achieve the above-mentioned purposes, the first oxynitridephosphor related to the present invention is characterized in consistingof a crystal containing at least one or more of Group II elementsselected from the group consisting of Be, Mg, Ca, Sr, Ba and Zn, atleast one or more of Group IV elements selected from the groupconsisting of C, Si, Ge, Sn, Ti, Zr and Hf, and a rare earth elementbeing an activator, R.

The first oxynitride phosphor related to the present invention has highluminescence brightness because it is a crystal in which elements arearranged according to a fixed rule, and has superior properties as aphosphor. Further, the first oxynitride phosphor related to the presentinvention can realize a desired luminescence spectrum at a blue green toyellow region by selecting its composition.

Wherein the oxynitride means a structure in which nitrogen is taken intoan oxide, and an amorphous oxynitride glass has been conventionallyknown as its typical example.

In the first oxynitride phosphor related to the present invention, inorder to realize higher brilliance, the fore-mentioned Group II elementsin which Ba is essential are one or more selected from the groupconsisting of Ca, Sr, Ba and Zn, the fore-mentioned Group IV elements inwhich Si is essential are one or more selected from the group consistingof C, Si, Ge, Sn, Ti, Zr and Hf, and the activator, R containspreferably Eu.

The first oxynitride phosphor containing Ba, Si and Eu has aluminescence spectrum having a luminescence peak at a blue green togreen region, and has extremely high luminescence efficiency andsuperior temperature properties.

Further, in this case, the content of the fore-mentioned activator, R ispreferably a molar ratio of the fore-mentioned Group II element: thefore-mentioned R=1:0.005 to 1:0.15 based on the fore-mentioned Group IIelement, in order to further realize high brightness, and theluminescence efficiency can be most highly enhanced at the composition.

In fore-mentioned first oxynitride phosphor, there is obtained aphosphor which is efficiently excited by light from an excitation lightsource and has a luminescence color at a blue green to yellow region, bycontaining O and N in the composition and setting the weight ratio ofsaid O and said N so that N is within a range of 0.2 to 2.1 per 1 of O.

The second oxynitride phosphor related to the present invention ischaracterized in being represented by the general formula,L_(X)M_(Y)O_(Z)N_(((2/3)X+(4/3)Y−(2/3)Z)):R orL_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+(4/3)Y+T−(2/3)Z)):R (L is at least one ormore of Group II elements selected from the group consisting of Be, Mg,Ca, Sr, Ba and Zn. M is at least one or more of Group IV elementsselected from the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf. Q isat least one or more of Group III elements selected from the groupconsisting of B, Al, Ga and In. O is an oxygen element. N is a nitrogenelement. R is a rare earth element. 0.5<X<1.5, 1.5<Y<2.5, 0<T<0.5, and1.5<Z<2.5).

The second oxynitride phosphor related to the present invention whichwas thus composed contains a crystal in which elements are at leastpartially arranged according to a fixed rule, light is efficientlyemitted from the crystal, and the phosphor has superior luminescentproperties. Further, since the luminescent portion of the secondoxynitride phosphor is not a glass body (amorphous) but a crystal, itcan reproduce stable properties, and its production and processing areeasy. Further, in the above-mentioned general formula, a crystal phasebeing the luminescent portion can be comparatively easily formed bysetting the fore-mentioned X, Y and Z within the above-mentioned range,and a phosphor having good luminescence efficiency can be provided.

The second oxynitride phosphor related to the present invention isexcited by light in a range from near ultraviolet to a short wavelengthside region of visible light and has a luminescence spectrum having aluminescence peak at a blue green to yellow region. Further, the secondoxynitride phosphor has the same stability or more in comparison with aYAG-base phosphor.

Hereat, the second oxynitride phosphor related to the present inventionresults also occasionally in a loss of nitrogen, and the general formulain that case is represented byL_(X)M_(Y)O_(Z)N_(((2/3)X+(4/3)Y−(2/3)Z−α)):R orL_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+(4/3)Y+T−(2/3)Z−α)):R (R≦α<1). Further,the nearer to zero the α is, the better the crystallinity of a crystalphase is, therefore the luminescence brightness is enhanced.

Further, in the second oxynitride phosphor related to the presentinvention, the fore-mentioned L in which Ba is essential is at least oneor more of Group II elements selected from the group consisting of Ca,Sr, Ba and Zn, M in which Si is essential is at least one or more ofGroup IV elements selected from the group consisting of C, Si, Ge, Sn,Ti, Zr and Hf, and Eu is preferably contained as the activator, R, inorder to realize the higher brightness.

Thus, the second oxynitride phosphor containing Ba, Si and Eu has aluminescence spectrum having a luminescence peak at a blue green togreen region.

The fore-mentioned X, the fore-mentioned Y and the fore-mentioned Z arepreferably X=1, Y=2, and Z=2. The more crystalline phases are formed atsaid composition, their crystallinity can be bettered, and theluminescence efficiency can be enhanced.

Thus, the second oxynitride phosphor related to the present inventionhas a crystal (a crystalline phase) at least partially, and the crystalis preferably contained by 50% by weight or more, and more preferably by80% by weight or more. Namely, the crystalline phases are a principalluminescent portion, and when the portion of the crystalline phasesbeing the luminescent portion is 50% by weight or more, luminescencewith good efficiency is obtained. Thus, the more the crystalline phasesare, the higher the luminescence brightness can be enhanced. Further,when the portion of the crystalline phases is much, its production andprocessing come to be easy.

The fore-mentioned crystals in the first and second oxynitride phosphorsof the present invention have the unit lattice of the rhombic systemaccording to a structural analysis by the X-ray diffraction pattern ofthe fore-mentioned phosphors, and it is grasped that they belong to therhombic system.

The rare earth metal element represented by the fore-mentioned R ispreferably Eu in order to obtain high luminescence efficiency, and whenEu and other rare earth elements are used, Eu is preferably 50% byweight or more among R, and more preferably 70% by weight or more inorder to obtain high luminescence efficiency.

The first and second oxynitride phosphors related to the presentinvention are excited by light from an excitation light source having aluminescence peak wavelength at 490 nm or less, and have luminescencespectra having luminescence peak wavelengths at a longer wavelength sidethan the fore-mentioned luminescence peak wavelength. Namely, the firstand second oxynitride phosphors are excited by light from an excitationlight source having a luminescence peak wavelength at 490 nm or less,and luminescence with good efficiency is obtained. The excitation lightsource for exciting the first and second oxynitride phosphors related tothe present invention has preferably a luminescence peak wavelength at240 to 470 nm, and more preferably a luminescence peak wavelength at 350to 410 nm.

The fore-mentioned first and second oxynitride phosphors are efficientlyexcited by light from the excitation light source having a luminescencepeak wavelength at 350 nm or more, and further 360 nm or more.

Further, when the fore-mentioned first and second oxynitride phosphorscontain Ba, Si and Eu, they are effectively excited by light from theexcitation light source having a luminescence peak wavelength at 360 nmto 480 nm, and can efficiently emit light having luminescence spectrahaving luminescence peak wavelengths at a longer wavelength side thanthe fore-mentioned luminescence peak wavelength.

Namely, when the fore-mentioned oxynitride phosphors contain Ba, Si andEu, those having luminescence peak wavelengths at 240 to 480 nm can beused as the excitation light source, but the excitation light sourcehaving a luminescence peak wavelength at 360 to 480 nm is preferablyused. In particular, it is preferable to use the excitation light sourcehaving a luminescence peak wavelength at 380 to 420 nm or 450 to 470 nmwhich is used in a semiconductor light-emitting element.

As described above, the luminescence spectra of the first and secondoxynitride phosphors related to the present invention can be set at ablue green to yellow region. Further, even if the YAG-base phosphorhaving a luminescence peak wavelength at a yellow region is excitedusing excitation light in a range from near ultraviolet to a shortwavelength side region of visible light (for example, excitation lighthaving a wavelength nearby 400 nm), it emits hardly light, but the firstand second oxynitride phosphors related to the present invention exhibithigh luminescence efficiency by the excitation light at said region.Additionally, when blue light is also used as the excitation lightsource, they exhibit high luminescence efficiency.

In the present specification, the blue green to yellow red region isrepresented according to JIS Z8110. Specifically, the blue green toyellow red region means a range of 485 to 610 nm.

The first and second oxynitride phosphors can have the excitationspectra in which luminescence intensity by light of 370 nm is higherthan luminescence intensity by light of 500 nm. When they are set thus,the phosphors excited by light at an ultraviolet region exhibit higherbrightness than the phosphors excited by light at a blue region. The useof light-emitting elements at an ultraviolet region can constitute alight-emitting device which can exhibit higher luminescence efficiencythan the use of light-emitting elements at a blue region.

When the first and second oxynitride phosphors contain Ba, Si and Eu, alight-emitting element nearby 460 nm can have the excitation spectrahaving higher intensity than that nearby 350 nm, and there can beconstituted the light-emitting device comprising a combination with alight-emitting element which emits visible light of a comparative shortwavelength.

The first and second oxynitride phosphors have preferably 2 or more ofGroup II elements selected from the group consisting of Be, Mg, Ca, Sr,Ba and Zn, and luminescence properties such as the color tone,luminescence brightness and quantum efficiency can be varied thereby torealize desired luminescence properties.

When the first and second oxynitride phosphors contain Sr and Ca, amolar ratio of Sr to Ca is preferably Sr:Ca=6:4 to 9:1. Further, whenthe oxynitride phosphors contain Sr and Ba, a molar ratio of Sr to Ba ispreferably Sr:Ba=6:4 to 9:1. Further, when the fore-mentioned first andsecond oxynitride phosphors contain Ca and Ba, a molar ratio of Ca to Bais preferably Ca:Ba=6:4 to 9:1. The oxynitride phosphors having variouscolor tones can be produced by selecting the combination and furtherselecting the composition ratio within the above-mentioned range.Further, the luminescence efficiency can be improved by selecting itwithin said range.

In the first and second oxynitride phosphors related to the presentinvention, the luminescence peak wavelength and color tone can be set bythe addition amount of the fore-mentioned activator R.

Namely, the first and second oxynitride phosphors related to the presentinvention can shift the luminescence peak wavelength to a shortwavelength side or a long wavelength side by controlling the additionamount of the activator, R, and additionally adjust the color tone.

When the luminescence peak wavelength and the color tone are varied bythe addition amount of the fore-mentioned activator R, the portion ofGroup II elements contained in the fore-mentioned oxynitride phosphorsis substituted with the fore-mentioned activator R, therefore the amountof the fore-mentioned activator R is preferably adjusted within a rangeof the molar ratio of (a mix amount of the fore-mentioned Group IIelements and the fore-mentioned activator R): (the amount of thefore-mentioned activator R)=1:0.001 to 1:0.8 based on the mix amount ofthe fore-mentioned Group II elements and the fore-mentioned activator R.The color tone can be varied while keeping the high luminescencebrightness by selecting it within said range. When Sr is used for thefore-mentioned Group II element, in particular, when the oxynitridephosphors related to the present invention are irradiated using anexcitation light source nearby 400 nm, the addition amount of theactivator R is preferably (a mix amount of the fore-mentioned Group IIelements and the fore-mentioned activator R): (the amount of thefore-mentioned activator R)=1:0.01 to 1:0.2. Further, when theoxynitride phosphors related to the present invention are irradiatedusing an excitation light source nearby 460 nm, the addition amount ofthe activator R is preferably (a mix amount of the fore-mentioned GroupII elements and the fore-mentioned activator R): (the amount of thefore-mentioned activator R)=1:0.02 to 1:0.26. When Ca is used for thefore-mentioned Group II element, in particular, when the oxynitridephosphors related to the present invention are irradiated using anexcitation light source nearby 400 nm, the addition amount of theactivator, R is preferably (a mix amount of the fore-mentioned Group IIelements and the fore-mentioned activator, R): (the amount of thefore-mentioned activator, R)=1:0.01 to 1:0.5. Further, when theoxynitride phosphors related to the present invention are irradiatedusing an excitation light source nearby 460 nm, the addition amount ofthe activator, R is preferably (a mix amount of the fore-mentioned GroupII elements and the fore-mentioned activator, R): (the amount of thefore-mentioned activator, R)=1:0.01 to 1:0.7. Because the oxynitridephosphors having high luminescence brightness can be provided byselecting it within said range. Further, the color tone x is shifted toa right direction and the color tone y is shifted to a down direction byincreasing the content of the activator, R in a chromaticity coordinate.The color tone can be varied thereby.

The production process of the oxynitride phosphors related to thepresent invention is characterized in having the first step thatmaterials containing the nitride of L (L is at least one or more ofGroup II elements selected from the group consisting of Be, Mg, Ca, Sr,Ba and Zn, the nitride of M (M is at least one or more of Group IVelements selected from the group consisting of C, Si, Ge, Sn, Ti, Zr andHf), the oxide of M, and the oxide of R (R is a rare earth element) aremixed, and the second step that the mixture obtained from the first stepis calcinated.

The phosphors easily produced and processed can be provided by theproduction process of the oxynitride phosphors related to the presentinvention. Further, the phosphors with extremely good stability can beprovided. Hereat, Li, Na, K, Rb, Cs, Mn, Re, Cu, Ag, Au and the like maybe contained in the mother body of the oxynitride phosphors prepared bythe production steps of the present production process or the presentproduction process. Provided that, the above-mentioned Li, Na, K and thelike are preferably 1000 ppm or less based on the weight of theoxynitride phosphors. More preferably, it is preferably 100 ppm or less.Because the high luminescence efficiency can be kept so far as it iswithin said range. Further, luminescence properties can be adjusted byenlarging the particle sizes of the appropriate amount of Li, Na, K andthe like, enhancing the luminescence brightness, and the like, and oncein a while, properties are occasionally improved. These Li, Na, K andthe like may be contained in the raw material composition. Because theabove-mentioned Li, Na, K and the like are scattered at the calcinationstep in the production steps of the oxynitride phosphors, and hardlycontained in said composition. Further, other elements may be containedto a degree which does not damage the properties.

In the present production process, the nitride of R is preferably usedin place of the fore-mentioned oxide of R, or together with thefore-mentioned oxide of R. The oxynitride phosphors with the highluminescence brightness can be provided thereby.

In the fore-mentioned first step, Q (Q is at least one of more of GroupIII elements selected from the group consisting of B, Al, Ga and In) isfurther preferably mixed. The particle diameter is enlarged thereby, andthe improvement of the luminescence brightness can be designed.

In the production process of the oxynitride phosphors related to thepresent invention, the fore-mentioned nitride of L, the fore-mentionednitride of M and the fore-mentioned oxide of M are preferably adjustedat molar ratios of 0.5< the nitride of L<1.5, 0.25< the nitride ofM<1.75 and 2.25< the oxide of M<3.75. The oxynitride phosphors with thecomposition of L_(X)M_(Y)O_(Z)N_(((2/3)X+(4/3)Y−(2/3)Z)):R orL_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+(4/3)Y+T−(2/3)Z)):R Can be providedthereby.

At least the portion of the raw material comprising the fore-mentionednitride of L is preferably substituted with at least either of the oxideof R and the nitride of R. The oxynitride phosphors with the highluminescence efficiency can be provided thereby.

The third oxynitride phosphor related to the present invention is anoxynitride phosphor produced by the production process of thefore-mentioned oxynitride phosphors.

As described above, the first to third oxynitride phosphors related tothe present invention have technical meanings that the phosphors whichare excited by light in a range from near ultraviolet to a shortwavelength side region of visible light and emit light at a blue greento yellow region can provided and the light-emitting device withextremely good luminescence efficiency can be provided by being combinedwith an appropriate excitation light source.

Namely, even if the YAG-base phosphor having the luminescence peakwavelength at a yellow system is emitted using the ultraviolet or nearultraviolet excitation light, it hardly emits light, but the oxynitridephosphors related to the present invention emit light by the excitationlight in a range from ultraviolet to a short wavelength side region ofvisible light, and exhibit the high luminescence efficiency.

Wherein the range from ultraviolet to the short wavelength side regionof visible light is not specifically limited, but means a region of 240to 500 nm or less. In particular, a range of 290 to 470 nm ispreferable. A range of 340 to 410 nm is more preferable.

Further, according to the present invention, there can be provided thecrystalline oxynitride phosphors which can be easily produced andprocessed. Further, there can be provided the oxynitride phosphorsexcellent in stability and reproducibility. Further, the new productionprocess of the oxynitride phosphors can be provided.

Further, the oxynitride phosphors containing Ba, Si and Eu related tothe present invention can provide phosphors with extremely goodluminescence efficiency which are excited by light in a range from nearultraviolet to a short wavelength side region of visible light and emitlight at a blue green to green region.

Further, the first light-emitting device related to the presentinvention is a light-emitting device having an excitation light sourceand a phosphor converting the wavelength of at least the portion oflight from said excitation light source, wherein the oxynitridephosphors having the luminescence peak wavelength at a blue green toyellow region are contained in the fore-mentioned phosphor. According tothe first light-emitting device, the light-emitting device having highluminescence efficiency can be provided.

Further, the second light-emitting device related to the presentinvention is a light-emitting device having an excitation light sourcewhich has a luminescence wavelength at a short wavelength region fromultraviolet to visible light and a phosphor which absorbs at least theportion of light from said excitation light source, converts thewavelength and has a luminescence color different from the luminescencecolor of the fore-mentioned excitation light source, wherein theoxynitride phosphors having the luminescence peak wavelength at a bluegreen to green region in which Ba is essential are contained in thefore-mentioned phosphor. According to this, the light-emitting devicehaving high luminescence efficiency and excellent in color rendering canbe provided. Further, the portion of light from the excitation lightsource having a luminescence wavelength at a short wavelength regionfrom ultraviolet to visible light and the portion of light from theoxynitride phosphor having the luminescence peak wavelength at a bluegreen to green region become color mixture light to be able to providethe light-emitting device having a luminescence color at a blue purpleto green region.

Further, in the first and second light-emitting devices related to thepresent invention, the fore-mentioned oxynitride phosphors arepreferably either of the first to third oxynitride phosphors related tothe present invention.

Further, there can be provided the light-emitting device having adesired color tone in which the luminescence peak wavelength and colortone are different can be provided by using the first to thirdoxynitride phosphors in which the luminescence peak wavelength and colortone were adjusted by the addition amount of the activator, R.

In the first and second light-emitting devices, the first to thirdoxynitride phosphors are excited by the excitation light source in arange from near ultraviolet to a short wavelength side region of visiblelight and absorb the portion of light from the excitation light source.The oxynitride phosphors which absorb said light and are excited carryout the wavelength conversion (the emission of light having a wavelengthdifferent from light absorbed). Said light whose wavelength wasconverted has a luminescence peak wavelength at a blue green to yellowregion. Namely, the fore-mentioned first to third oxynitride phosphorsabsorb the portion of light from light-emitting elements and emit lighthaving luminescence spectra having luminescence peak wavelengths at ablue green to yellow region. Further, said first to third oxynitridephosphors have high luminescence efficiency, extremely efficientlyconvert the wavelengths of light from light-emitting elements, and canemit light. Further, there can be also provided the light-emittingdevice having an intermediate color between the luminescence color ofthe light-emitting elements and the luminescence color of the oxynitridephosphors by the color mixture of light from the light-emitting elementswith light from the first to third oxynitride phosphors.

When the fore-mentioned first to third oxynitride phosphors contain Oand N and the weight ratio of said O to said N is N of 0.2 to 2.1 basedon 1 of O, they are efficiently excited by the light-emitting elementsat near ultraviolet and the like.

The aforementioned excitation light source has preferably at least oneor more of luminescence peak wavelengths in a range from ultraviolet toa short wavelength side region of visible light. Because theluminescence efficiency of the fore-mentioned phosphors can be enhancedby using the excitation light source having said range. In particular,the excitation light sources having the luminescence peak wavelengths at240 to 470 nm are preferably used, and among these, the excitation lightsources having the luminescence peak wavelengths at 350 to 410 nm arepreferably used.

The fore-mentioned excitation light source is preferably light-emittingelements. Namely, the light-emitting elements are small size, have goodelectric power efficiency, and emit bright color light. Further, saidlight-emitting elements have no fear of a burnt-out light bulb becauseof a semiconductor element. Further, they have characteristics that theyare superior in initial drive property and resistant in vibration andthe repetition of on-off lighting. Accordingly, it is preferable in thepresent invention to combine the light-emitting elements with theoxynitride phosphors.

The luminescent layer of the fore-mentioned light-emitting elements haspreferably a nitride semiconductor containing In. The light-emittingelements release light having the luminescence peak wavelengths at 350to 410 nm, and the fore-mentioned oxynitride phosphors are efficientlyexcited by the light from said light-emitting elements to exhibit afixed luminescence color. Since the luminescence with high intensity isobtained by being excited by light nearby 350 to 410 nm, thelight-emitting elements at said wavelength region are suitable. Further,since the light-emitting elements can make the width of the luminescencespectra narrow, the oxynitride phosphors can be efficiently excited, andlight substantially having no color tone change can be released from thelight-emitting device.

The first and second light-emitting devices related to the presentinvention may include the second phosphor together with thefore-mentioned oxynitride phosphors as the fore-mentioned phosphor. Thesecond phosphor in the present invention preferably carries out thewavelength conversion of at least the portion of light from thefore-mentioned excitation light sources and the fore-mentionedoxynitride phosphors. Thus, there can be provided the light-emittingdevice having a luminescence color at a visible light region by thecolor mixture of the light from the fore-mentioned excitation lightsources, the fore-mentioned oxynitride phosphors and light from thesecond phosphor. The light-emitting device thus constituted can releasea desired luminescence color so far as it is within a wavelength regionfrom the luminescence color of the excitation light sources to theluminescence color of the oxynitride phosphors or the luminescence colorof the second phosphor.

The second phosphor may have at least one or more of the luminescencepeak wavelengths from a blue region to green, yellow and red regions inorder to realize a desired luminescence color (the luminescence color asthe light-emitting device). In particular, various luminescence colorscan be realized by combining three primary colors of the green color ofthe oxynitride phosphors which were excited by the excitation lightsources having the luminescence peak wavelengths in a range fromultraviolet to a short wavelength side region of visible light, with theblue color and red color of the second phosphor. Further, thelight-emitting device may be a light-emitting device comprising thecombination of 2 kinds of colors such as a green color with red colorand a green color with yellow color.

The fore-mentioned second phosphor is preferably at least one or moreselected from an alkali earth halogen apatite phosphor, an alkali earthmetal borate halogen phosphor, an alkali earth metal aluminate phosphor,an alkali earth silicate, an alkali earth sulfide, an alkali earththiogallate, an alkali earth silicone nitride, and a germanic acid saltwhich are mainly activated by elements such as the Lanthanide serieselement such as Eu and a transition metal-base element such as Mn; or arare earth aluminate and a rare earth silicate which are mainlyactivated by the Lanthanide series element such as Ce; an organic andorganic complex which are mainly activated by elements such as theLanthanide series element such as Eu. The light-emitting device havingthe high luminescence brightness and high luminescence efficiency suchas quantum efficiency can be provided thereby. Further, thelight-emitting device having good color rendering can be provided.Provided that the second phosphor is not limited by the abovedescriptions, and can use phosphors which emit light having variouscolor tastes.

The light-emitting device containing the fore-mentioned second phosphorreleases preferably light by mixing at least 2 or more of lights amongthe portion of the light from the fore-mentioned excitation lightsource, the light from the fore-mentioned oxynitride phosphor and thelight from the fore-mentioned second phosphor. The luminescence color ofthe light-emitting device is adjusted thereby, and a desiredluminescence color can be released. In particular, when thelight-emitting elements which emit light at an ultraviolet region areused, the luminescence color at the ultraviolet region can be hardlyviewed by human eyes. Accordingly, the luminescence color by mixing thelight from the fore-mentioned oxynitride phosphor and the light from thefore-mentioned second phosphor is exhibited. Since said luminescencecolor is determined only by the phosphor, the adjustment of theluminescence color is extremely carried out easily. Wherein the phosphoris represented as the second phosphor, but the second phosphor is notlimited to only one kind, and several kinds of phosphors may becontained. The finer chromaticity adjustment is possible by containingseveral kinds of phosphors. Further, in particular, when thelight-emitting elements at a short wavelength region from ultraviolet tovisible light are used, the lights from said light-emitting elements arelittle felt as a color taste for human eyes, therefore the deviation ofchromaticity caused by production deviation can be lessened.

The luminescence color of the light-emitting device containing thefore-mentioned second phosphor can be set at an intermediateluminescence color from the peak wavelength which the fore-mentionedexcitation light source has, to the peak wavelength which thefore-mentioned oxynitride phosphors have, or the peak wavelength whichthe fore-mentioned second phosphor has. The excitation light source hasthe luminescence spectrum at a shorter wavelength side than theoxynitride phosphors or the second phosphor, and has high energy. Thelight-emitting device containing the fore-mentioned second phosphor canrelease the luminescence color from the high energy region to the lowenergy region of the oxynitride phosphors and the second phosphor. Inparticular, it exhibits the luminescence color from the luminescencepeak wavelength of light-emitting elements to the first luminescencepeak wavelength of the oxynitride phosphors, or the second luminescencepeak wave which the second phosphor has. For example, when theluminescence peak wavelength of the light-emitting elements is situatedat a blue region, the luminescence peak wavelength of the oxynitridephosphors excited is situated at a green region, and the luminescencepeak wavelength of the second phosphor excited is situated at a redregion, a white luminescence color can be exhibited by the color mixtureof three colors. As a different example, when the luminescence peakwavelength of the light-emitting elements is situated at an ultravioletregion, the luminescence peak wavelength of the oxynitride phosphorsexcited is situated at a green region, and the luminescence peakwavelengths of the second phosphor excited are situated at yellow andred regions, a slightly yellowish white luminescence color and amulti-color base luminescence color can be realized. The luminescencecolor from a color taste nearby the luminescence color of the oxynitridephosphors, to a color taste nearby the luminescence color of the secondphosphor can be realized by changing the compounding amount of theoxynitride phosphors and the second phosphor. Further, when the secondphosphor has 2 or more of the luminescence peak wavelengths, there isrealized the light-emitting device exhibiting a luminescence colorbetween the luminescence peak wavelength which the light-emittingelements have, the luminescence peak wavelength which the oxynitridephosphors have, and 2 or more of the luminescence peak wavelengths whichthe second phosphor has. The second phosphor is not only used alone, butalso 2 or more can be used in combination. Not only a light-emittingdevice emitting white light but also a light-emitting device emittinglight with various color tastes such as a pastel color have beenrecently desired. According to the light-emitting device of the presentinvention, there can be provided the light-emitting device having adesired color taste by variously combining the oxynitride phosphorswhich emit green light, the phosphor which emits red light, and thephosphor which emits blue light. In the light-emitting device related tothe present invention, various color tastes can be realized not only bya process of changing the kind of phosphors, but also by a process ofchanging the compounding ratio of phosphors combined, a process ofchanging the coating process of phosphors on an excitation light source,a process of adjusting the lighting time of an excitation light source,and the like.

When a white color system is selected as the fore-mentioned intermediateluminescence color, it is preferable a white color nearby the locus ofblack body radiation in particular. The white color base light-emittingdevice can be used for various uses such as illuminations, the backlight of liquid crystal and displays.

The fore-mentioned light-emitting device has preferably the luminescencespectrum having one or more of the luminescence peak wavelengths atleast at 430 to 500 nm and 500 to 730 nm. There can be provided thelight-emitting device which emits light having a desired color taste bycombining blue light, green light and red light. Accordingly, the colorrendering can be improved by combining several phosphors. In case of thesame white color luminescence, there exist also a yellowish white colorand a bluish white color. Accordingly, the light-emitting device has theluminescence spectrum having the luminescence peak wavelength within theabove-mentioned range.

As described above, the light-emitting device related to the presentinvention has technical meanings that the oxynitride phosphors which areexcited by the light-emitting elements at an ultraviolet to visiblelight region and in which the wavelength is converted are used and anexcellent light-emitting device can be provided. Said oxynitridephosphors have high luminescence efficiency and are stable phosphorswith high reproducibility. Further, the light-emitting device has atechnical meaning that a light-emitting device having a desiredluminescence color by combining the light-emitting elements, theoxynitride phosphors and the second phosphor can be provided.

Further, in the present specification, the relation between thewavelength range of light and the color name of single light is inaccordance with JIS Z8110. Specifically, 380 to 455 nm is a blue purplecolor, 455 to 485 nm is a blue color, 485 to 495 nm is a blue greencolor, 495 to 548 nm is a green color, 548 to 573 nm is a yellow greencolor, 573 to 584 nm is a yellow color, 584 to 610 nm is a yellow redcolor, and 610 to 780 nm is a red color.

Further, the second light-emitting device related to the presentinvention is preferably a light-emitting device having a luminescencespectrum having at least one or more of the luminescence peakwavelengths at 360 to 485 nm, 485 to 548 nm and 548 to 730 nm. There canbe provided the light-emitting device which emits light with a desiredcolor taste by combining a blue color, a green color, a red color andthe like which are three primary colors. Further, the color renderingcan be improved by combining several phosphors. Because in case of thesame white color luminescence, there exist also a yellowish white colorand a bluish white color.

The fore-mentioned second light-emitting device is preferably alight-emitting device having a luminescence spectrum having at least oneor more of the luminescence peak wavelengths at 360 to 485 nm and 485 to548 nm. For example, there can be obtained the light-emitting devicewhich emits white light by combining a blue light-emitting element and aYAG-base phosphor, but light nearby 500 nm is insufficient. Accordingly,there can be provided the light-emitting device having excellent colorrendering by containing the oxynitride phosphor which emits light nearby500 nm.

The fore-mentioned second light-emitting device is preferably theaverage rendering index (Ra) of 80 or more. The light-emitting devicehaving excellent color rendering can be provided thereby. In particular,the light-emitting device whose specific color rendering (R9) wasimproved can be provided.

As described above, a bright luminescence color can be realized by thefirst and second light-emitting devices related to the presentinvention. In particular, the oxynitride phosphor exhibits aluminescence color at a blue green to yellow region by the light fromthe light-emitting element having ultraviolet light. Further, there canbe provided the light-emitting device having excellent luminescenceproperties by changing the composition ratio of the oxynitride phosphor.Further, there can be provided the light-emitting device having highluminescence efficiency and excellent reproducibility. Further, thecolor tone can be changed by changing the compounding ratio of theactivator, R (in particular, Eu). Further, there can be provided theoxynitride phosphor having excellent luminescence brightness and quantumefficiency by changing the compounding ratio of Eu. Accordingly, thepresent invention has an extremely important technical meaning that thelight-emitting device described above can be provided.

Further, according to the second light-emitting device related to thepresent invention, there can be provided the light-emitting device whichemits bright blue to green light. Further, there can be produced thelight-emitting device which combined said oxynitride phosphor, theYAG-base phosphor being the second phosphor, and the blue light-emittingelement. There can be provided the light-emitting device havingexcellent color rendering and extremely high luminescence efficiency,thereby. With respect to said color rendering, the specific colorrendering index (R9) which exhibits a red color is improved inparticular.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the cannonball type light-emitting device 1 ofEmbodiment 2 related to the present invention;

FIG. 2A is a plane view showing the surface mounting type light-emittingdevice of Embodiment 3 related to the present invention, and FIG. 2B isa section view showing the surface mounting type light-emitting deviceof Embodiment 3 related to the present invention;

FIG. 3 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 1 to 5 were excited at Ex=400 nm;

FIG. 4 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 1 to 5 were excited at Ex=460 nm;

FIG. 5 is a chart showing the excitation spectra of the oxynitridephosphors of Examples 1 to 5;

FIG. 6 is a chart showing the reflection spectra of the oxynitridephosphors of Examples 1 to 5;

FIG. 7 is an SEM photo photographing the oxynitride phosphor of Example1;

FIG. 8 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 6 to 10 were excited at Ex=400 nm;

FIG. 9 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 6 to 10 were excited at Ex=460 nm;

FIG. 10 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 11 to 15 were excited at Ex=400 nm;

FIG. 11 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 11 to 15 were excited at Ex=460 nm;

FIG. 12 is a chart showing the excitation spectra of the oxynitridephosphors of Examples 11 to 15;

FIG. 13 is a chart showing the reflection spectra of the oxynitridephosphors of Examples 11 to 15;

FIG. 14 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 10 and 16 to 20 were excited at Ex=400 nm;

FIG. 15 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 10 and 16 to 20 were excited at Ex=460 nm;

FIG. 16 is a chart showing the excitation spectra of the oxynitridephosphors of Examples 10 and 16 to 20;

FIG. 17 is a chart showing the reflection spectra of the oxynitridephosphors of Examples 10 and 16 to 20;

FIG. 18 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 21 to 24 were excited at Ex=400 nm;

FIG. 19 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 21 to 24 were excited at Ex=460 nm;

FIG. 20 is a chart showing the excitation spectra of the oxynitridephosphors of Examples 21 to 24;

FIG. 21 is a chart showing the reflection spectra of the oxynitridephosphors of Examples 21 to 24;

FIG. 22 is a schematic view showing the rhombic system;

FIG. 23 is a chart showing the X-ray diffraction pattern of theoxynitride phosphor of Example 25;

FIG. 24 is a chart showing the X-ray diffraction pattern of theoxynitride phosphor of Example 26;

FIG. 25 is a chart showing the X-ray diffraction pattern of theoxynitride phosphor of Example 27;

FIG. 26 is a plane view showing the light-emitting element related tothe present invention;

FIG. 27 is a section view showing the A-A′ of the light-emitting elementrelated to the present invention;

FIG. 28 is a chart showing the luminescence spectrum of thelight-emitting device of Example 28 related to the present invention;

FIG. 29 is a chart showing the chromaticity coordinate of thelight-emitting device of Example 28 related to the present invention;

FIG. 30 is a chart showing the cap type light-emitting device of Example30 related to the present invention;

FIG. 31 is a process chart showing the production process of theoxynitride phosphor;

FIG. 32 is a chart showing the change of the luminescence efficiencycaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor;

FIG. 33 is a chart showing the change of the luminescence efficiencycaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor;

FIG. 34 is a CIE chromaticity chart showing the change of the color tonecaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor;

FIG. 35 is an expanded CIE chromaticity chart of FIG. 34;

FIG. 36 is a chart showing the luminescence spectrum when the oxynitridephosphor was excited at Ex=400 nm;

FIG. 37 is a chart showing the luminescence spectrum when the oxynitridephosphor was excited at Ex=460 nm;

FIG. 38 is a chart showing the normalized excitation spectrum of theoxynitride phosphor;

FIG. 39 is a chart showing the reflection spectrum of the oxynitridephosphor;

FIG. 40A is an SEM photo photographed the oxynitride phosphor of Example36 at a magnification of 1000-fold, FIG. 40B is an SEM photophotographed the oxynitride phosphor of Example 36 at a magnification of5000-fold, and FIG. 40C is an SEM photo photographed the oxynitridephosphor of Example 36 at a magnification of 10000-fold;

FIG. 41 is a chart showing the change of the luminescence efficiencycaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor;

FIG. 42 is a chart showing the change of the luminescence efficiencycaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor;

FIG. 43 is a CIE chromaticity chart showing the change of the color tonecaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor;

FIG. 44 is an expanded CIE chromaticity chart of FIG. 43;

FIG. 45 is a chart showing the luminescence spectrum when the oxynitridephosphor was excited at Ex=400 nm;

FIG. 46 is a chart showing the luminescence spectrum when the oxynitridephosphor was excited at Ex=460 nm;

FIG. 47 is a chart showing the normalized excitation spectrum of theoxynitride phosphor;

FIG. 48 is a chart showing the reflection spectrum of the oxynitridephosphor;

FIG. 49 is a chart showing the change of the peak intensity caused bythe change of the content of the activator R contained in thecomposition of the oxynitride phosphors;

FIG. 50 is a chart showing the change of the luminescence efficiencycaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphors;

FIG. 51 is a chart showing the luminescence spectra when the oxynitridephosphors were excited at Ex=400 nm;

FIG. 52 is a chart showing the luminescence spectra when the oxynitridephosphors were excited at Ex=460 nm;

FIG. 53 is a chart showing the normalized excitation spectra of theoxynitride phosphors;

FIG. 54 are a chart showing the reflection spectra of the oxynitridephosphors;

FIG. 55 is a chart showing the luminescence spectrum when the oxynitridephosphor of Example 79 was excited at Ex=400 nm;

FIG. 56 is a chart showing the luminescence spectrum when the oxynitridephosphor of Example 79 was excited at Ex=460 nm;

FIG. 57 is a chart showing the normalized excitation spectrum of theoxynitride phosphor of Example 79;

FIG. 58 is a chart showing the reflection spectrum of the oxynitridephosphor of Example 79;

FIG. 59A is an SEM photo photographed the oxynitride phosphor of Example79 at a magnification of 1000-fold, and

FIG. 59B is an SEM photo photographed the oxynitride phosphor of Example79 at a magnification of 10000-fold;

FIG. 60 is a chart showing the luminescence spectrum of thelight-emitting device 1 related to the present invention;

FIG. 61 is a chromaticity chart showing the chromaticity coordinate ofthe light-emitting device 1 related to the present invention;

FIG. 62 is a process chart showing the production process of theoxynitride phosphor;

FIG. 63 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 83 to 87 were excited at Ex=400 nm;

FIG. 64 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 83 to 87 were excited at Ex=460 nm;

FIG. 65 is a chart showing the excitation spectra of the oxynitridephosphors of Examples 83 to 87;

FIG. 66 is a chart showing the reflection spectra of the oxynitridephosphors of Examples 83 to 87;

FIG. 67 is an SEM photo photographing the oxynitride phosphor of Example83;

FIG. 68 is a chart showing the luminescence spectrum (simulation) of thelight-emitting device of Example 88;

FIG. 69 is a chart showing the chromaticity coordinates (simulation) ofthe light-emitting devices of Examples 88 to 90;

FIG. 70 is a chart showing the luminescence spectra (simulation) of thelight-emitting devices of Examples 89 and 90; and

FIG. 71 is a chart showing the luminescence spectra of thelight-emitting devices of Examples 91 and 92.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The light-emitting device related to the present invention and theoxynitride phosphor used for said light-emitting device, and theproduction process are illustrated below using the modes of operationand Examples. Provided that the present invention is not limited toembodiments and examples.

Embodiment 1

Embodiment 1 relates to the oxynitride phosphor which is suitable forbeing used in combination with a light-emitting element, in particular,a nitride semiconductor element, and the phosphor is a phosphor which isexcited by the light of a nitride semiconductor light-emitting elementand generates light having a wavelength different from the light fromthe light-emitting element.

The oxynitride phosphor related to Embodiment 1 uses a rare earthelement, and is a phosphor comprising an oxynitride phosphor crystalcontaining at least one or more of Group II elements selected from thegroup consisting of Be, Mg, Ca, Sr, Ba and Zn, and at least one or moreof Group IV elements selected from the group consisting of C, Si, Ge,Sn, Ti, Zr and Hf.

Wherein the oxynitride phosphor crystal is an oxynitride phosphorcomprising, for example, crystal which belongs to the rhombic system andis shown in the later-mentioned examples.

The combination of Group II elements and Group IV elements described inthe above description is arbitrary, but the combinations below arepreferably used.

The oxynitride phosphor of Embodiment 1 is represented by the generalformula of L_(X)M_(Y)O_(Z)N_(((2/3)X+(4/3)Y−(2/3)Z)):R, orL_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+(4/3)Y+T−(2/3)Z)):R.

Wherein L is at least one or more of Group II elements selected from thegroup consisting of Be, Mg, Ca, Sr, Ba and Zn. M is at least one or moreof Group IV elements selected from the group consisting of C, Si, Ge,Sn, Ti, Zr and Hf. Q is at least one or more of Group III elementsselected from the group consisting of B, Al, Ga and In. O is an oxygenelement. N is a nitrogen element. R is a rare earth element. 0.5<X<1.5,1.5<Y<2.5, 0<T<0.5, and 1.5<Z<2.5.

The oxynitride phosphor which is represented by the general formula cancontain the crystal in which elements are at least partially arrangedaccording to a fixed rule, and light having high brightness isefficiently emitted from the crystal. In the above-mentioned generalformula, a crystal phase being the luminescent portion can becomparatively easily formed by setting as 0.5<X<1.5, 1.5<Y<2.5, 0<T<0.5,and 1.5<Z<2.5, and the phosphor having good luminescence efficiency andhigh brightness can be provided.

Further, in the above-mentioned general formula, X, Y and Z arepreferably X=1, Y=2, and Z=2. The more crystalline phases are formed atsaid composition, its crystallinity can be bettered, and theluminescence efficiency and brightness can be enhanced. The proportionof crystals (crystalline phases) contained in the oxynitride phosphor ofEmbodiment 1 is preferably 50% by weight or more and more preferably 80%by weight or more.

Further, when the proportion of crystals contained is desired to be setat a fixed value in order to adjust the luminescence brightness and thelike, it can be also adjusted by the values of X, Y and Z in theabove-mentioned general formula.

However, the above-mentioned range is a preferable range, and thepresent invention is not limited to the above-mentioned range.

Specifically, in the oxynitride phosphor of the present invention, thereare contained oxynitride phosphors represented by CaSi₂O₂N₂:Eu,SrSi₂O₂N₂:Eu, BaSi₂O₂N₂:Eu, ZnSi₂O₂N₂:Eu, CaGe₂O₂N₂:Eu, SrGe₂O₂N₂:Eu,BaGe₂O₂N₂:Eu, ZnGe₂O₂N₂:Eu, Ca_(0.5)Sr_(0.5)Si₂O₂N₂:Eu,Ca_(0.5)Ba_(0.5)Si₂O₂N₂:Eu, Ca_(0.5)Zn_(0.5)Si₂O₂N₂:Eu,Ca_(0.5)Be_(0.5)Si₂O₂N₂:Eu, Sr_(0.5)Ba_(0.5)Si₂O₂N₂:Eu,Ca_(0.8)Mg_(0.2)Si₂O₂N₂:Eu, Sr_(0.8)Mg_(0.2)Si₂O₂N₂:Eu,Ca_(0.5)Mg_(0.5)Si₂O₂N₂:Eu, Sr_(0.5)Mg_(0.5)Si₂O₂N₂:Eu,CaSi₂B_(0.1)O₂N₂:Eu, SrSi₂B_(0.1)O₂N₂:Eu, BaSi₂B_(0.1)O₂N₂:Eu,ZnSi₂B_(0.1)O₂N₂:Eu, CaGe₂B_(0.01)O₂N₂:Eu, SrGe₂G_(0.01)O₂N₂:Eu,BaGe₂In_(0.01)O₂N₂:Eu, ZnGe₂Al_(0.05)O₂N₂:Eu,Ca_(0.5)Sr_(0.5)Si₂B_(0.3)O₂N₂:Eu, CaSi_(2.5)O_(1.5)N₃:Eu,SrSi_(2.5)O_(1.5)N₃:Eu, BaSi_(2.5)O_(1.5)N₃:Eu,Ca_(0.5)Ba_(0.5)Si_(2.5)O_(1.5)N₃:Eu,Ca_(0.5)Sr_(0.5)Si_(2.5)O_(1.5)N₃:Eu, Ca_(1.5)Si_(2.5)O_(2.5)N_(2.7):Eu,Sr_(1.5)Si_(2.5)O_(2.5)N_(2.7):Eu, Ba_(1.5)Si_(2.5)O_(2.5)N_(2.7):Eu,Ca_(1.0)Ba_(0.5)Si_(2.5)O_(1.5)N₃:Eu,Ca_(1.0)Sr_(0.5)Si_(2.5)O_(1.5)N₃:Eu, Ca_(0.5)Si_(1.5)O_(1.5)N_(1.7):Eu,Sr_(0.5)Si_(1.5)O_(1.5)N_(1.7):Eu, Ba_(0.5)Si_(1.5)O_(1.5)N_(1.7):Eu,Ca_(0.3)Ba_(0.2)Si_(2.5)O_(1.5)N₃:Eu,Ca_(0.2)Sr_(0.3)Si_(2.5)O_(1.5)N₃:Eu and the like.

Further, as shown here, the oxynitride phosphor of Embodiment 1 canchange a ratio of O to N, and the color tone and brightness can beadjusted by changing the ratio. Further, a molar ratio of cation toanion which is shown by (L+M)/(O+N) can be also changed, and theluminescence spectrum and intensity can be finely adjusted thereby. Thiscan be carried out, for example, by carrying out treatment such asvacuum and removing N and O, but the present invention is not limited tothis process. In the composition of the oxynitride phosphor, there maybe contained at least one or more of Li, Na, K, Rb, Cs, Mn, Re, Cu, Agand Au, and the brightness and luminescence efficiency such as quantumefficiency can be adjusted by adding these. Further, other elements maybe contained so far as the properties are not damaged.

The portion of Group II elements contained in the oxynitride phosphor issubstituted with the activator R. The amount of the fore-mentioned theactivator R is preferably in molar ratio of (a mix amount of thefore-mentioned Group II elements and the fore-mentioned activator, R):(the amount of the fore-mentioned activator, R)=1:0.001 to 1:0.8 basedon a mix amount of the fore-mentioned Group II elements and thefore-mentioned activator, R.

Further, L is at least one or more of Group II elements selected fromthe group consisting of Be, Mg, Ca, Sr, Ba and Zn. In the presentinvention, L may be single bodies such as Ca and Sr, and may comprisethe combination of a plural number of elements such as Ca and Sr, Ca andBa, Sr and Ba, and Ca and Mg. Further, when L is the combination ofplural number of elements, the composition ratio can be varied. Forexample, the compounding ratio can be varied for the mixture of Sr andCa, if necessary.

In particular, L is preferably at least one or more of Group II elementsselected from the group consisting of Mg, Ca, Sr, Ba and Zn in whicheither of Ca, Sr and Ba is essential.

M is at least one or more of Group IV elements selected from the groupconsisting of C, Si, Ge, Sn, Ti, Zr and Hf. M may be also single bodiessuch as Si and Ge, and may comprise the combination of a plural numberof elements such as Si and Ge, and Si and C. In the present invention,the above-mentioned Group IV elements can be used but Si and Ge arepreferably used. The phosphor having good crystallinity and low cost canbe provided using Si and Ge.

In particular, M is preferably at least one or more of Group IV elementsselected from the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf inwhich Si is essential.

R is rare earth elements. Specifically, R is one or 2 or more elementsselected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.In the present invention, Eu is preferably used among these rare earthelements. Further, Eu and at least one or more elements selected fromrare earth elements may be contained. In that case, Eu is preferablycontained by 50% by weight or more as R, and more preferably 70% byweight or more. Namely, the activator R is preferably at least one ormore elements selected from the group consisting of La, Ce, Pr, Nd, Sm,Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in which Eu is essential. Becauseelements other than Eu acts as a co-activator.

In Embodiment 1, europium Eu being the rare earth elements is used as aluminescence center. Europium has mainly a divalent and trivalent energylevels. The phosphor of Embodiment 1 uses Eu²⁺ as the activator for analkali earth metal silicone nitride being the mother body. Eu²⁺ iseasily oxidized and commercially available as the composition of Eu₂O₃in general.

Further, in the present specification, the phosphor using Eu being atypical example as the luminescence center is occasionally illustrated,but the present invention is not limited to this.

L and M of the main components can be also used as compounds thereof asthe mother material. These L and M of the main components can be used asmetals, oxides, imides, amides, nitrides, and various salts. Further,the elements of L and M of the main components may be preliminarilymixed to be used.

Q is at least one or more of Group III elements selected from the groupconsisting of B, Al, Ga and In. Q is also used as metals, oxides,imides, amides, nitrides, and various salts. For example, they are B₂O₆,H₃BO₃, Al₂O₃, Al(NO₃)₃.9H₂O, AlN, GaCl₃, InCl₃ and the like.

The nitride of L, the nitride of M and the oxide of M are mixed as themother body materials. The oxide of Eu is mixed with said mother bodymaterials as the activator. These are weighed so as to be the desiredphosphor composition, and mixed until being homogeneous. In particular,the nitride of L, the nitride of M and the oxide of M in the mother bodymaterials are preferably mixed at molar ratios of 0.5< the nitride ofL<1.5, 0.25< the nitride of M<1.75, and 2.25< the oxide of M<3.75.Namely, the fixed amounts of these mother body materials are weighed andmixed so as to be the composition ratio ofL_(X)M_(Y)O_(Z)N_(((2,3)X+Y−(2,3)Z−α)):R orL_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+Y+T−(2/3)Z−α)):R.

(Production Process of Oxynitride Phosphor)

Then, the production process of the oxynitride phosphor related toEmbodiment 1, CaSi₂O₂N₂:Eu is illustrated. Further, the presentinvention is not limited to the production processes below.

Firstly, the nitride of Ca, the nitride of Si, the oxide of Si and theoxide of Eu are prepared. As these raw materials, those purified arepreferably used, but those commercially available may be used.

1. Preparation of Nitride of Ca

Firstly, Ca of a raw material is crushed. The Ca of a raw material ispreferably used as a single body, but compounds such as an imidecompound, an amide compound and CaO can be also used. Further, the Ca ofa raw material may be those containing B, Ga and the like. The crushingof the Ca of a raw material is carried out in a globe box in argonatmosphere. It is preferable that the mean particle diameter of Caobtained by the crushing is about 0.1 μm to 15 μm, but is not limited tothis range. The purity of Ca is preferably 2N or more, but is notlimited to this range.

Then, the Ca of a raw material crushed is nitrided in nitrogenatmosphere. The nitride of Ca can be obtained by nitriding the Cacrushed at a temperature of 600 to 900° C. for about 5 hours in nitrogenatmosphere. The reaction is shown in Formula 1.3Ca+N₂→Ca₃N₂  [Formula 1]

As the nitride of Ca, it is needless to say that those with high purityare preferable. As the nitride of Ca, those commercially available canbe also used.

Then the nitride of Ca is crushed. The crushing of the nitride of Ca iscarried out in a globe box in argon atmosphere or in nitrogenatmosphere.

2. Preparation of Nitride of Si

Firstly, the Si of a raw material is crushed. The Si of a raw materialis preferably used as a single body, but a nitride compound, an imidecompound, an amide compound and the like can be also used. For example,they are Si₃N₄, Si(NH₂)₂, Mg₂Si, Ca₂Si, SiC and the like. The purity ofthe Si of a raw material is preferably 3N or more, but B, Ga and thelike may be contained. The crushing of Si of a raw material is carriedout in a globe box in argon atmosphere or in nitrogen atmosphere, inlike manner as the Ca of a raw material. It is preferable that the meanparticle diameter of the Si compound is about 0.1 μm to 15 μm.

The Si of a raw material is nitrided in nitrogen atmosphere. Silicon, Siis also nitrided at a temperature of 800 to 1200° C. for about 5 hoursin nitrogen atmosphere to obtain silicon nitride. The reaction formulais shown in Formula 2.3Si+2N₂→Si₃N₄  [Formula 2]

It is needless to say that the silicon nitride used in the presentinvention is preferably those having high purity. Further, those whichare commercially available can be also used.

Then, the nitride of Si is crushed.

3. Preparation of Oxide of Si

As SiO₂ being the oxide of Si, those which are commercially availableare used (Silicon Dioxide 99.9%, 190-09072, manufactured by Wako PureChemicals Industries, Ltd.).

Raw materials (the nitride of Ca, the nitride of Si, the oxide of Si,and the oxide of Eu) which were purified or produced as above areweighed so as to be a fixed molar amount.

Then, the weighed raw materials are mixed.

Then, the mixture of the nitride of Ca, the nitride of Si, the oxide ofSi, and the oxide of Eu is calcined at about 1500° C. in ammoniaatmosphere. The calcined mixture is charged in a crucible to becalcined.

The oxynitride phosphor represented by CaSi₂O₂N₂:Eu can be obtained bymixing and calcination. The reaction formula of the basic constitutingelements by the calcination is shown in Formula 3.(1/3)Ca₃N₂+(1/3)Si₃N₄+SiO₂+aEu₂O₃→CaSi₂O₂N₂:Eu  [Formula 3]

However, the composition is a typical composition deduced from thecompounding ratio, and has adequate properties which are worthwhile forpractical use, around the ratio. Further, the composition of theobjective phosphors can be changed by changing the compounding ratio ofthe respective raw materials.

The calcination can use a tube furnace, a small size furnace, a highfrequency furnace and a metal furnace and the like. The calcinationtemperature is not specifically limited. The calcination is preferablycarried out at a temperature of 1200 to 1700° C., and a calcinationtemperature of 1400 to 1700° C. is more preferable. It is preferable tocarry out the calcination of the raw materials of the phosphor using acrucible made of boron nitride (BN) material and a boat. A crucible madeof alumina (Al₂O₃) material can be also used in addition to the cruciblemade of boron nitride material.

Further, reductive atmosphere is inactive gas atmospheres such asnitrogen atmosphere, nitrogen-hydrogen atmosphere, ammonia atmosphereand argon atmosphere, etc.

The objective oxynitride phosphor can be obtained by using the aboveproduction process.

Further, the oxynitride phosphor represented byCa_(X)Si_(Y)B_(T)O_(Z)N_(((2/3)X+Y+T−(2/3)Z−α)):Eu which contains B canbe produced as below.

A B compound, H₃BO₃ is preliminarily mixed with the oxide of Eu in drycondition. Europium oxide is used as the Eu compound, but metaleuropium, europium nitride and the like can be also used in like manneras the fore-mentioned other constitution elements. Additionally, animide compound, a amide compound and the like can be used as the Eucompound. Europium oxide is preferably those having high purity, butthose commercially available can be also used. A B compound is mixed ina dry process but a wet mixing can be also carried out.

The production process of the oxynitride phosphor is illustratedexemplifying the B compound H₃BO₃. However, there are Li, K, Na and thelike as the component constituting elements other than B, and as thesecompounds, for example, there can be used LiOH.H₂O, Na₂CO₃, K₂CO₃, RbCl,CsCl, Mg(NO₃)₂, CaCl₂.6H₂O, SrCl₂.6H₂O, BaCl₂.2H₂O, TiOSO₄.H₂O,ZrO(NO₃)₂, HfCl₄, MnO₂, ReCl₅, Cu(Ch₃COO)₂.H₂O, AgNO₃, HAuCl₄.4H₂O,Zn(NO₃)₂.6H₂O, GeO₂, Sn(CH₃COO)₂ and the like.

A mixture of Eu and B is crushed. The mean particle diameter of themixture of Eu and B after the crushing is preferably about 0.1 μm to 15μm.

After the above-mentioned crushing, the nitride of Ca, the nitride ofSi, the oxide of Si, and the oxide of Eu containing B are mixed in likemanner as the fore-mentioned production steps of CaSi₂O₂N₂:Eu. Aftersaid mixing, calcination is carried out and the objective oxynitridephosphor can be obtained.

The above oxynitride phosphors of Embodiment 1 have stability equal toor more than the YAG-base phosphor, and further have the characteristicsbelow.

(1) The oxynitride phosphors of Embodiment 1 can set a desiredluminescence color within a comparative wide range from a blue greenregion to a yellow red region by selecting the composition andcomposition ratio, and can widely adjust the color tone, luminescencebrightness, quantum efficiency and the like.

For example, the color tone, luminescence brightness and quantumefficiency can be adjusted by changing the ratio using 2 or more ofGroup II elements.

(2) Although the YAG-base phosphor hardly emits light by excitation bylight at a visible region from ultraviolet to short wavelength, theoxynitride phosphors of Embodiment 1 obtains high luminescenceefficiency by excitation by light at a visible region from ultravioletto short wavelength.

Namely, there can be provided the phosphor which is suitable forcombination with a light-emitting element emitting light at a visibleregion from ultraviolet to short wavelength by the oxynitride phosphorsof Embodiment 1.

(3) Since the oxynitride phosphor is crystalline, it can be easilyproduced as powder or particles, therefore its treatment and processingare easy.

Embodiment 2

FIG. 1 is a section view showing the constitution of the light-emittingdevice of Embodiment 2 related to the present invention, and the presentlight-emitting device has at least a light-emitting element and thefirst phosphor converting the wavelength of at least the portion oflight from said light-emitting element. Hereat, in particular, thelight-emitting device of Embodiment 2 is characterized in using theoxynitride phosphors of Embodiment 1 as the first phosphor.

Further, in the present specification, the relation between the name ofcolor and the chromaticity coordinate is according to JIS Z8110.

In the light-emitting device of Embodiment 2, a light-emitting element10 is composed of a sapphire substrate 1, a semiconductor layer 2 formedon the sapphire substrate 1, and positive and negative electrodes formedon the semiconductor layer 2. The light-emitting element 10 isdie-bonded in the cup of the lead frame 13 a, and the positive andnegative electrodes are respectively connected with the lead frame 13 aand the lead frame 13 b by the electro-conductive wire 14. Further, thecoating member 12 containing the phosphor 11 is formed in the cup of thelead frame 13 a so as to cover the light-emitting element 10. Further,the mold member 15 is formed so as to cover the whole of the lead frame13 a and the lead frame 13 b in which the coating member containing thelight-emitting element and the phosphor 11 was provided.

In the light-emitting device of Embodiment 2, the semiconductor layer 2of the light-emitting element 10 comprises a plural number of layersincluding a luminescent layer (not illustrated), and the composition ofthe luminescent layer is adjusted so that the luminescence peakwavelength becomes 500 nm or less at an ultraviolet to blue region.Further, the positive and negative electrodes 3 are formed on the sameplane side of said semiconductor layer 2.

The light-emitting device of Embodiment 2 is prepared below.

Firstly, the light-emitting element 10 is set in a die bonder, andface-up is carried out for the lead frame 13 a to be die-bonded(adhered). After the die-bonding, the lead frames 13 are transferred toa wire bonder, the negative electrode 3 of the light-emitting element iswire-bonded by a gold wire with the lead frame 13 a which was providedin the cup, and the positive electrode 3 is wire-bonded with anotherlead frame 13 b.

Then, it is transferred to a mold equipment, and the phosphor 11 and thecoating member 12 are injected in the cup of the lead frames 13 with thedispenser of the mold equipment. At this time, the phosphor 11 and thecoating member 12 are preliminarily mixed at a fixed proportionhomogeneously.

After coating, the lead frames 13 are immersed in a mold frame where themold member 15 was preliminarily injected, then the mold frame isremoved and a resin is cured to prepare the cannonball typelight-emitting device which is shown in FIG. 1.

The respective constituting members of the light-emitting device ofEmbodiment 2 are specifically illustrated below.

(Phosphor 11)

The phosphor 11 includes the oxynitride phosphors of Embodiment 1.Further, those combining the oxynitride phosphors and the secondphosphor can be used as the phosphor 11.

(Light-Emitting Element 10)

In Embodiment 2, the light-emitting element 10 is preferably asemiconductor light-emitting element having a luminescent layer whichemits light with a wavelength which can excite the oxynitride phosphorefficiently. As the material of the semiconductor light-emittingelement, there can be mentioned various semiconductors such as BN, SiC,ZnSe, GaN, InGaN, InAlGaN, AlGaN, BAlGaN and BInAlGaN. Further, aluminescence center can be also made by containing Si, Zn and the likein these elements as impurity elements. As the semiconductor materialwhich can efficiently emit light at a short wavelength region among anultraviolet region and a visible light region which can efficientlyexcite the phosphor 11 (oxynitride phosphor), there can be preferablymentioned nitride semiconductors (for example, a nitride semiconductorcontaining Al and Ga, In_(X)Al_(Y)Ga_(1-X-Y)N, 0≦X, 0≦Y, X+Y≦1 as anitride semiconductor containing In and Ga).

Further, as the structure of the semiconductor light-emitting element,there are preferably mentioned semiconductors having a homo structure, ahetero structure or a double hetero structure having an MIS junction, aPIN junction, a p-n junction and the like. A luminescence wavelength canbe variously selected by the material of semiconductor layers and mixcrystal ratio. Further, output power can be also further improved bymaking a single quantum well structure and a multi quantum wellstructure in which a semiconductor activating layer was formed to be athin film which generates quantum effect.

When the light-emitting element 10 is composed of the nitridesemiconductor, there are preferably used a substrate comprisingmaterials such as sapphire, spinel, SiC, Si, ZnO, GaAs and GaN. Thesapphire substrate is preferably used for forming the nitridesemiconductor having good crystallinity by mass production. The nitridesemiconductor can be formed on the sapphire substrate using a HVPEprocess, a MOCVD process and the like. Specifically, an amorphous bufferlayer in which GaN, AlN, GaAlN and the like were grown at a lowtemperature is formed on the sapphire substrate, and the nitridesemiconductor having a p-n junction is formed thereon.

The preparation example of the light-emitting element capable ofefficiently emitting light at an ultraviolet region which has a p-njunction using the nitride semiconductor is as below.

Firstly, SiO₂ is formed in a stripe form about perpendicular to anorientation flat face of a sapphire substrate on the buffer layer. Then,ELOG (Epitaxial Lateral Over Grows GaN) growth of GaN is carried out onit using an HVPE process. Successively, the first contact layer formedwith n-GaN, the first clad layer formed with n-AlGaN, active layershaving a multi quantum well structure which laminated a plural number oflayers of the well layers of InAlGaN and the barrier layers of AlGaN,the second clad layer formed with p-AlGaN, and the second contact layerformed with formed with p-GaN are laminated in order by the MOCVDprocess. Thus, the nitride semiconductor light-emitting element having adouble hetero structure is prepared.

Further, the semiconductor laser element which can be utilized for thepresent invention can be prepared by making the active layer be ridgestripe form, sandwiching it with guide layers, and providing the edgeface of a resonator.

Further, the nitride semiconductor exhibits an n-type conductivity in acondition in which impurities are not doped, but Si, Ge, Se, Te, C andthe like are appropriately introduced as an n-type dopants in order toform an n-type nitride semiconductor having a desired carrier levels forpurposes of improving the luminescence efficiency and the like. On theother hand, when a p-type nitride semiconductor is formed, Zn, Mg, Be,Ca, Sr, Ba and the like which are p-type dopants are preferably doped.Further, since the nitride semiconductor is hardly converted to p-typeonly by doping the p-type dopants, it is preferable to lower theresistance by heating with a furnace, plasma irradiation and the likeafter introducing the p-type dopants. When the sapphire substrate is notremoved, the portion of the first contact layer is exposed by etchingfrom a p-type side to the surface of the first contact layer, andelectrodes are respectively formed on the respective contact layers.Then, the light-emitting elements comprising the nitride semiconductor(for example, the nitride semiconductor light-emitting element having astructure shown in FIG. 1) are prepared by cutting in a chip shape fromthe semiconductor wafer.

When the phosphor 11 is fixed around the surface of the light-emittingelement 10 in the light-emitting device of Embodiment 2, a resin (atransparent resin) is preferably utilized for forming in good massproductivity. In this case, when both of the relation with theluminescence wavelength of the phosphor 11 and the deteriorationprotection of the transparent resin are considered, the light-emittingelement 10 having a luminescence spectrum at an ultraviolet region,whose luminescence peak wavelength is 360 nm or more and 420 nm or less,or 450 nm or more and 470 nm or less, is preferably used.

Hereat, the semiconductor light-emitting element 10 used in Embodiment 2is preferably adjusted so that the sheet resistance Rn of an n-typecontact layer in which impurity levels are 10¹⁷ to 10²⁰/cm³ and thesheet resistance Rp of a transparent p-type electrode become therelation of the sheet resistance of Rp≧Rn. The n-type contact layer ispreferably formed at a film thickness of 3 to 10 μm and more preferably4 to 6 μm, and the sheet resistance Rn is estimated to be 10 to 15Ω/□.Accordingly, it is preferable to set the thickness so that the sheetresistance Rp of the transparent p-type electrode is 10 to 15Ω/□.Specifically, the transparent p-type electrode may be formed at a thinfilm thickness of 150 μm or less.

Further, when the transparent p-electrode is formed by one kind selectedfrom a group of gold and platinum and a multilayered film or alloycomprising at least one kind of other elements, stability andreproducibility are improved by adjusting the sheet resistance of thetransparent p-electrode by the content of gold or platinum elementcontained. Since gold or a metal element has a high absorptioncoefficient at the wavelength of the semiconductor light-emittingelement used for the present invention, the lesser the amount of gold orplatinum element contained in the transparent p-electrode is, the betterthe transparency is. A conventional semiconductor light-emitting elementhad the relation of the sheet resistance of Rp≦Rn, but since it is Rp≧Rnin Embodiment 2, the transparent p-electrode is formed in a thinner filmin comparison with a conventional one. The thin film forming can beeasily attained by reducing the amount of gold or platinum element.

As described above, the semiconductor light-emitting element used forthe present invention has preferably the relation of Rp≧Rn for the sheetresistance RnΩ/□ of n-contact layer and the sheet resistance RnΩ/□ ofthe transparent p-electrode. However, since it is difficult to measureRn after preparing the semiconductor light-emitting element 10, it issubstantially impossible to know the relation of Rp and Rn, but it ispossible to know what relation exists between Rp and Rn from thecondition of light intensity distribution at light emission.

When the transparent p-electrode and n-contact layer have the relationof Rp≧Rn, it is preferable to provide a p-side pedestal electrode havingan extended conduction portion in contact with the fore-mentionedtransparent p-electrode, therefore the external quantum efficiency canbe further improved. The shape and direction of the extended conductionportion is not limited, and when the extended conduction portion is alinear shape, an area obstructing light is preferably reduced, but theshape may be a mesh shape. The shape may be a curve, a lattice, a branchand a hook other than the linear shape. Hereat, since the shading effectis increased in proportion to the total area of the p-side pedestalelectrode, it is preferable to design the line width and length of theextended conduction portion so that the shading effect does not exceedsthe luminescence increasing effect.

As described above, not only a light-emitting element emittingultraviolet light, but also a light-emitting element emitting blue lightcan be also used as the light-emitting element 10 in Embodiment 2. Thelight-emitting element 10 emitting blue light is also preferably GroupIII nitride compound light-emitting element. For example, suchlight-emitting element 10 has a laminated structure in which an Siundoped n-GaN layer, an n-contact layer comprising Si-doped n-GaN, anundoped n-GaN layer, a luminescent layer having a multi quantum wellstructure (the multi quantum well structure of GaN barrier layer/InGaNwell layer), a p-clad layer comprising Mg-doped p-GaN, and a p-contactlayer comprising Mg-doped p-GaN are laminated in order on a sapphiresubstrate through GaN buffer layer. Further, electrodes are formed asbelow. Provided that the light-emitting elements different from theconstitution can be also used.

A p-Ohmic electrode is formed almost all over the surface on thep-contact layer, and a p-pad electrode is formed on the portion of thep-ohmic electrode.

Further, the undoped GaN layer is removed from the p-contact layer byetching, the portion of the n-contact layer is exposed, and then-electrode is formed on the exposed portion.

Further, the luminescent layer having a multi quantum well structure wasused in Embodiment, but the present invention is not limited to this.For example, it may be a single quantum well structure utilizing InGaN,and GaN to which Si, Zn and the like were doped may be utilized.

Further, in the luminescent layer of the light-emitting element 10, themain luminescence peak wavelength can be varied within a range of 420 nmto 490 nm by changing the content of In. Further, the luminescence peakwavelength is not limited to the above-mentioned range, and those havingthe luminescence peak wavelength the luminescence peak wavelength at 360to 550 nm can be also used.

(Coating Member 12)

The coating member 12 (transparent material) is provided in the cup ofthe lead frames 13, and used by being mixed with the phosphor 11. As thespecific material of the coating member 12, there are used transparentresins excellent in temperature property and weather resistance such asan epoxy resin, a urea resin and a silicone resin; silica sol, glass, aninorganic binder and the like. Further, a dispersant, barium titanate,titanium oxide, aluminum oxide and the like may be contained togetherwith the phosphor. Further, a light stabilizer and a coloring agent maybe contained.

(Lead Frame 13)

The lead frame 13 is constituted by the mount lead 13 a and the innerlead 13 b.

The mount lead 13 a arranges the light-emitting element 10. The upperpart of the mount lead 13 a is a cup shape, and the light-emittingelement 10 is die-bonded in the cup. The light-emitting element 10 iscovered in the cup with the fore-mentioned phosphor 11 and thefore-mentioned coating member 12. Further, a plural number of thelight-emitting elements 10 are arranged in the cup, and the mount lead13 a can be utilized as a common electrode of the plural number of thelight-emitting elements 10. In this case, an adequateelectroconductivity and the connecting property of the electroconductivewire 14 are required. The die bonding (adhesion) of the light-emittingelement 10 with the cup of the mount lead 13 a can be carried out by athermosetting resin and the like. As the thermosetting resin, an epoxyresin, an acryl resin, an imide resin and the like are mentioned.Further, it is die-bonded with the mount lead 13 a by the face downlight-emitting element 10 and the like, and an Ag paste, a carbon paste,a metal bump and the like can be used for carrying out electricconnection. Further, an inorganic binder can be also used.

The inner lead 13 b is electrically connected with the electroconductivewire 14 which is extended from the electrode 3 of the light-emittingelements 10 which were arranged on the mount lead 13 a. The inner lead13 b is preferably arranged at a position which is separated from themount lead 13 a for preventing a short circuit with the mount lead 13 a.When a plural number of the light-emitting elements 10 are arranged onthe mount lead 13 a, a constitution in which the respective wires arenot mutually connected is required. The inner lead 13 b uses preferablythe similar material as that of the mount lead 13 a, and iron, copper,copper with iron, gold, platinum, silver and the like can be used.

(Electroconductive Wire)

The electroconductive wire 14 connects electrically the electrode 3 ofthe light-emitting elements 10 with the lead frame 13. Theelectroconductive wire 14 is preferably those having good ohmicproperty, mechanical connecting property and heat conductivity with theelectrode 3. The specific material of the electroconductive wire 14 ispreferably metals such as gold, copper, platinum, aluminum and the like,and alloys thereof, etc.

(Coating Member 12)

The phosphor 11 can be adhered using various coating members (binder)such as the resins of organic materials and glass of inorganicmaterials. The coating member 12 has occasionally a role as a binder forfixing the phosphor 11 on the light-emitting element 10, the windowportion 107 and the like. When an organic substance is used as thecoating member (binder), as the specific material, there are preferablyused transparent resins excellent in weather resistance such as an epoxyresin, an acryl resin and a silicone resin. When a silicone is used, itis preferable because it is superior in reliability and thedispersibility of the phosphor 11 can be improved.

Further, when an inorganic substance having the similar thermalexpansion coefficient as the window portion 107 is used as the coatingmember 12 (binder), it is preferable because the phosphor 108 can beadhered on the fore-mentioned window portion 107. As the specificprocesses, there can be used a sedimentation process, a sol-gel process,a spray process and the like. For example, silanol (Si(OEt)₃OH) andethanol are mixed with the phosphors 11 and 108 to form a slurry, theslurry is vomited from a nozzle, then the mixture is heated at 300° C.for 3 hours to convert silanol into SiO₂, and the phosphor can be fixedon a desired position.

Further, the binding agent being an inorganic substance can be also usedas the coating members (binder) 12 and 109. The binding agent is aso-called low melting point glass and fine particles, and preferablyabsorbs little radiation at an ultraviolet to visible region and isextremely stable in the coating members (binders) 12 and 109.

When the phosphor having large particle diameters is adhered with thecoating members (binders) 12 and 109, there are preferably used bindingagents in which particles are ultra fine powder even if its meltingpoint is high, such as for example, silica sol, alumina, or alkali earthmetal pyrophosphate and phosphate having a fine particle size which isobtained by a sedimentation process. These binding agents can be usedalone or they are mutually mixed to be used.

Hereat, the coating process of the above-mentioned binding agent isdescribed. In order to sufficiently enhance binding effect, the bindingagent is preferably crushing in a vehicle in wet condition to prepare aslurry, and used as a binding agent slurry. The fore-mentioned vehicleis a highly viscous solution which is obtained by dissolving a smallamount of an adhesive binding agent in an organic solvent or deionizedwater. For example, an organic-base vehicle is obtained by containing 1%by weight of nitrocellulose being the adhesive binding agent based onbutyl acetate being an organic solvent.

The phosphors 11 and 108 are contained in the binding agent slurry thusobtained to prepare a coating solution. As the addition amount of theslurry in the coating solution, the total amount of the binding agent inthe slurry can be 1 to 3% by weight based on the phosphor amount in thecoating solution. It is preferable that the addition amount of thebinding agent is little in order to suppress the lowering of a beamretention rate.

The fore-mentioned coating solution is coated on the back face of thefore-mentioned window portion 107. Then, warm wind or hot wind is blownto dry it. Finally, baking is carried out at a temperature of 400° C. to700° C. to disperse the fore-mentioned vehicle. Thus, the phosphor layeris adhered on a desired position with the binding agent.

(Mold Member)

The mold member 15 is provided for protecting the light-emittingelements 10, the phosphor 11, the coating member 12, the lead frame 13,the electroconductive wire 14 and the like from the external. The moldmember 15 has purposes of expanding the angle of visibility, reducingthe directionality from the light-emitting elements 10, and focusing andscattering luminescence in addition to the purpose of protection fromthe external. In order to attain the purposes, the mold member can beformed in a desired shape. Further, the mold member 15 may be a convexlens shape, a concave lens shape, additionally, a structure in which aplural number of layers were laminated. As the specific material of themold member 15, there can be used materials excellent in transmissionproperty, weather resistance and temperature property such as an epoxyresin, a urea resin, a silicone resin, a silica sol, a glass, and thelike. A dispersant, a coloring agent, an ultraviolet absorbent and aphosphor be contained in the mold member 15. As the dispersant, bariumtitanate, titanium oxide, aluminum oxide and the like are preferable.The same material is preferably used for reducing the repulsion of thecoating member 12 with the material and for considering a refractiveindex.

According to the light-emitting device of Embodiment 2 which wasconstituted above, a light-emitting device having various luminescencecolors can be realized.

For example, in the light-emitting device of Embodiment 2, thelight-emitting device having the same luminescence color as theluminescence color of the oxynitride phosphor can be realized bycombining an ultraviolet light-emitting element with the oxynitridephosphor.

Further, the light-emitting device having a luminescence color between(intermediate) the luminescence color of a light-emitting element andthe luminescence color of the oxynitride phosphor can be realized bycombining a blue light-emitting element with the oxynitride phosphor.

Further, the light-emitting device of Embodiment 2 can realize alight-emitting device having various color tones because the oxynitridephosphor related to the present invention can adjust the luminescencecolor, luminescence brightness and the like at a wide range.

Furthermore, the light-emitting device of Embodiment 2 can provide alight-emitting device having the high brightness and high luminescenceefficiency because the oxynitride phosphor related to the presentinvention can emit light having high brightness and the luminescenceefficiency is high.

Embodiment 3

FIG. 2 is a plane view showing the surface mounting type light-emittingdevice of Embodiment 3 related to the present invention (FIG. 2A and asection view (FIG. 2B)). The light-emitting device of Embodiment 3 is asurface mounting type light-emitting device. In the light-emittingdevice of Embodiment 3, a nitride semiconductor light-emitting elementwhich emits light at an ultraviolet region can be used as thelight-emitting element 101, and a nitride semiconductor light-emittingelement which emits light at a blue region can be also used. Further,the specific constitution is similar as the light-emitting element ofEmbodiment 2.

Hereat, the light-emitting element 101 which emits light at anultraviolet region is illustrated as an example. In Embodiment 3, thelight-emitting element 101 is a nitride semiconductor light-emittingelement which has an InGaN semiconductor whose luminescence peakwavelength is about 370 nm as a luminescent layer. The more specific LEDelement structure has a structure in which a luminescent layer having asingle quantum well structure including an n-GaN layer being an undopednitride semiconductor, a GaN layer in which an Si doped n-electrode isformed to be an n-contact layer, an n-GaN layer being an undoped nitridesemiconductor, an n-AlGaN layer being a nitride semiconductor and anInGaN well layer was laminated on a sapphire substrate. An AlGaN layeras an Mg doped p-clad layer and a GaN layer being an Mg doped p-contactlayer are laminated in order on the luminescent layer. Further, a bufferlayer which was obtained by growing a GaN layer at low temperature isformed on a sapphire substrate. Further, the p-semiconductor is annealedat 400° C. or more after coating. In the above-mentioned laminatedstructure, the surfaces of the respective p-n-contact layers are exposedon the nitride semiconductor on the sapphire substrate by etching at thesame face side. An n-electrode is formed in a belt shape on then-contact layer exposed, and a transparent p-electrode comprising ametal thin film is formed on almost the whole surface of the residualp-contact layer. Further, a pedestal electrode is formed on thetransparent p-electrode in parallel with the n-electrode using aspattering process.

In Embodiment 3, there is used the package 105 made of kovar having aconcave portion at a central part and comprising a base portion in whichthe lead electrode 102 made of kovar was inserted to be fixed ininsulating hermetic seal at the both sides of the fore-mentioned concaveportion. An Ni/Ag layer is provided on the surfaces of thefore-mentioned package 105 and the lead electrode 102. Theabove-mentioned light-emitting element 101 is die-bonded in the concaveportion of the package 105 with an Ag—Sn alloy. All of the constitutionmembers of the light-emitting device can be made by inorganic substancesby composing thus, therefore even if the luminescence released from thelight-emitting element 101 was at an ultraviolet region or a visiblelight short wavelength region, the light-emitting device having greatlyhigh reliability is obtained.

Then, the respective electrodes of the light-emitting element 101die-bonded are electrically connected with the respective leadelectrodes 102 exposed from the bottom face of the package concaveportion, with the Ag wire 104 respectively. After sufficiently removingmoisture in the package concave portion, it is sealed with the lid 106made of kovar which has the glass window portion 107 at a centralportion to carry out seam welding. The phosphor 108 containingCaSi₂O₂N₂:Eu, (Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce and the like is preliminarilycontained in a slurry consisting of 90% by weight of nitrocellulose and10% by weight of γ-alumina, the mixture is coated on the back face ofthe transparent window portion 107 of the lid 106, and the colorconversion member is constituted by curing by heating at 220° C. for 30minutes. When light is emitted from the light-emitting device thusformed, there can be prepared a light-emitting diode which can emitwhite light at high brightness. There can be prepared the light-emittingdevice which adjusts extremely easily chromaticity and is excellent inproductivity and reliability, thereby. The respective constitutions ofthe present invention are specifically illustrated.

Further, when an inorganic substance having the similar thermalexpansion coefficient as the window portion 107 is used as the coatingmember 12 (binder), it is preferable because the phosphor 108 can beadhered on the fore-mentioned window portion 107. As the adheringprocesses, there can be used a sedimentation process, a sol-gel process,a spray process and the like. For example, silanol (Si(OEt)₃OH) andethanol are mixed with the phosphor 108 to form a slurry, said slurry isvomited from a nozzle, then the mixture is heated at 300° C. for 3 hoursto convert silanol into SiO₂, and the phosphor can be fixed on a desiredposition.

Further, the binding agent being an inorganic substance can be also usedas the coating member (binder) 109. The binding agent is a so-called lowmelting point glass and fine particles, and preferably absorbs littleradiation at an ultraviolet to visible region and is extremely stable inthe coating member (binder) 109.

The light-emitting device of Embodiment 3 which was constituted abovehas the similar action effect as Embodiment 2.

Embodiment 4

The light-emitting device of Embodiment 4 is a light-emitting device inwhich the second phosphor is contained together with the oxynitridephosphor as the phosphors 11 and 108 in the light-emitting device ofEmbodiment 2 or 3.

The second phosphor is preferably at least one or more selected from analkali earth halogen apatite phosphor, an alkali earth metal boratehalogen phosphor, an alkali earth metal aluminate phosphor, an alkaliearth silicate, an alkali earth sulfide, an alkali earth thiogallate, analkali earth silicone nitride, and a germanic acid salt which are mainlyactivated by elements such as the Lanthanide series element such as Euand a transition metal-base element such as Mn; or a rare earthaluminate and a rare earth silicate which are mainly activated by theLanthanide series element such as Ce; an organic and organic complexwhich are mainly activated by elements such as the Lanthanide serieselement such as Eu. As the specific example, phosphors below can bementioned, but the present invention is not limited to these.

As the alkali earth halogen apatite phosphor which is mainly activatedby elements such as the Lanthanide series element such as Eu and atransition metal-base element such as Mn, there are M₅(PO₄)₃X:R (M is atleast one or more selected from Sr, Ca, Ba, Mg and Zn. X is at least oneor more selected from F, Cl, Br and I. R is at least one or more of Eu,Mn, and Eu and Mn.) and the like.

As the alkali earth metal borate halogen phosphor, there are M₂B₅O₉X:R(M is at least one or more selected from Sr, Ca, Ba, Mg and Zn. X is atleast one or more selected from F, Cl, Br and I. R is at least one ormore of Eu, Mn, and Eu and Mn.) and the like.

As the alkali earth metal aluminate phosphor, there are SrAl₂O₄:R,Sr₄Al₁₄O₂₅:R, CaAl₂O₄:R, BaMg₂Al₁₆O₂₇:R, BaMg₂Al₁₆O₁₂:R, BaMgAl₁₀O₁₇:R(R is at least one or more of Eu, Mn, and Eu and Mn.) and the like.

As the alkali earth sulfide phosphor, there are La₂O₂S:Eu, Y₂O₂S:Eu,Gd₂O₂S:Eu and the like.

As the rare earth aluminate phosphor which is mainly activated by theLanthanide series element such as Ce, there are YAG-base phosphorsrepresented by the composition formulae of Y₃Al₅O₁₂:Ce(Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce, Y₃(Al_(0.8)Ga_(0.2))₅O₁₂:Ce and (Y,Gd)₃(Al, Ga)₅O₁₂:Ce; and the like.

As other phosphors, there are ZnS:Eu, Zn₂GeO₄:Mn, MGa₂S₄:Eu (M is atleast one or more selected from Sr, Ca, Ba, Mg and Zn. X is at least oneor more selected from F, Cl, Br and I.) and the like. Further, there arealso M₂Si₅N₈:Eu, MSi₇N₁₀:Eu, M_(1.8)Si₅O_(0.2)N₈:Eu,M_(0.9)Si₇O_(0.1)N₁₀:Eu (M is at least one or more selected from Sr, Ca,Ba, Mg and Zn.) and the like.

The above-mentioned second phosphor can contain one or more selectedfrom Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni and Ti, in place of Eu, or inaddition to Eu if necessary.

Further, phosphors other than the above-mentioned phosphors which havethe similar performances and effects can be also used.

As these second phosphors, there can be used phosphors which haveluminescence spectra at a red color, a green color and a blue color bythe excitation light of the light-emitting elements 10 and 101, andadditionally, there can be also used phosphors which have luminescencespectra at a yellow color, a blue green color and an orange color whichare intermediate colors. There can be produced the light-emitting devicehaving various luminescence colors by using these second phosphors incombination with the first phosphor.

For example, there can be provided the light-emitting device with goodcolor rendering which emits white light by using the phosphors 11 and108 comprising CaSi₂O₂N₂:Eu or SrSi₂O₂N₂:Eu being the first phosphorwhich emits green to yellow light, (Sr, Ca)₅(PO₄)₃Cl:Eu being the secondphosphor which emits blue light, and (Ca, Sr)₂Si₅N₈:Eu. Because red,blue and green which are three primary colors of color are used,therefore a desired white light can be realized only by changing thecompounding ratio of the first phosphor and the second phosphor.

In particular, when light nearby 460 nm as an excitation light source isirradiated to the oxynitride phosphor and the second phosphor, theoxynitride phosphor emits light around 500 nm. There can be provided thewhite color light-emitting device with good color rendering, thereby.

The particle diameter of the above-mentioned phosphors 11 and 108 ispreferably 1 μm to 20 μm, more preferably 2 μm to 8 μm, and preferably 5μm to 8 μm in particular. A phosphor having a particle diameter of 2 μmor less is apt to form aggregates. On the other hand, a phosphor havinga particle diameter of 5 μm to 8 μm has the high absorption rate andconversion efficiency of light. Thus, the mass productivity of thelight-emitting device is improved by containing the phosphors having alarge particle diameter which have optically superior properties.

Wherein the particle diameter means the mean particle diameter obtainedby an air transmission process. Specifically, a sample by 1 cm³ isweighed under environments of a temperature of 25° C. and a humidity of70% and packed in an exclusive use tubular container, then dry air atfixed pressure is flown, and a specific surface area is read fromdifferential pressure to obtain a value converted to the mean particlediameter. The mean particle diameter of the phosphors used in thepresent invention is preferably 2 μm to 8 μm. Further, the phosphorhaving the value of the mean particle diameter is preferably containedin high frequency. Further, those whose particle size distribution isnarrow are preferable, and those having fine particles with 2 μm or lessare preferable in particular. Thus, the light-emitting devicesuppressing color unevenness and having good color tone is obtained byusing phosphors having the little unevenness of the particle diameterand particle size distribution.

The position of arranging the phosphor 108 in the light-emitting deviceof FIG. 2 can be arranged at various positions in the positionalrelation with the light-emitting element 101. For example, the phosphor108 can be contained in a mold material coating the light-emittingelement 101. Further, the light-emitting element 101 and the phosphor108 may be arranged at an interval, and the phosphor 108 may be directlymounted on the upper part of the light-emitting element 101.

The light-emitting device of Embodiment 4 which was constituted abovehas the similar effect as the light-emitting device of Embodiment 2, andadditionally, has effects below.

Namely, in the light-emitting device of Embodiment 4, the light-emittingdevice having a luminescence color by the color mixture of theluminescence of the oxynitride phosphor and the luminescence of thesecond phosphor, or the light-emitting device having a luminescencecolor by the color mixture of the luminescence of a light-emittingelement (a light-emitting element emitting visible light), theluminescence of the oxynitride phosphor and the luminescence of thesecond phosphor can be realized by using the second phosphor in additionto the oxynitride phosphor.

Further, in the light-emitting device of Embodiment 4, the adjustment ofthe luminescence color, luminescence brightness and the like comes to bepossible by changing the kind of the second phosphor and the ratio tothe oxynitride phosphor, and the more kind of the color tones than themodes of operation 2 and 3 can be realized.

Embodiment 5

Embodiment 5 related to the present invention is the production processof the oxynitride phosphor represented by SrSi₂O₂N₂:Eu, and FIG. 31 is aprocess chart showing the production process of the oxynitride phosphorof Embodiment 5.

In the present production process, firstly, the nitride of Sr, thenitride of Si, the oxide of Si and the oxide of Eu are prepared. Asthese raw materials, those purified are preferably used, but thosecommercially available may be used. Specifically, the oxynitridephosphor is produced by the process below.

Sr₃N₂ as a nitride is used for the Sr of a raw material. As the rawmaterial, compounds such as an imide compound, an amide compound, SrOand the like can be also used, and Sr single body can be used. Further,the Sr of a raw material may be those containing B, Ga and the like.

The nitride of Sr, Sr₃N₂ is crushed (P1).

Sr₃N₄ is used as the nitride of Si being a raw material. As the rawmaterial, other nitride compound, an imide compound, an amide compoundand the like can be also used, and an Si single body can be also used.For example, they are Si(NH₂)₂, Mg₂Si, Ca₂Si, SiC and the like. Thepurity of the Si of a raw material is preferably 3N or more, but B, Gaand the like may be contained.

The nitride of Si, Si₃N₄ is crushed (P2).

SiO₂ is used as the oxide of Si of a raw material. Hereat, those whichare commercially available are used (Silicon Dioxide 99.9%, 190-09072,manufactured by Wako Pure Chemicals Industries, Ltd.).

Oxide of Si, SiO₂ is crushed (P3).

The oxide of Eu, Eu₂O₃ is used for a raw material. The single body of Euis preferably used as the raw material, but a nitride compound, an imidecompound, an amide compound and the like can be used. In particular, aneuropium nitride is preferably used in addition to an europium oxide.Because oxygen or nitrogen is contained in a product.

Oxide of Eu, Eu₂O₃ is crushed (P4)

After crushing the respective raw materials, the fixed molar amount ofthe nitride of Sr, Sr₃N₂, the nitride of Si, Si₃N₄, the oxide of Si,SiO₂, and the oxide of Eu, Eu₂O₃ are weighed so as to be a fixedcompounding ratio, and mixed (P5).

Then, the mixture of the nitride of Sr, the nitride of Si, the oxide ofSi, and the oxide of Eu is calcinated (P6). Said mixture is charged in acrucible and calcination is carried out.

The oxynitride phosphor represented by SrSi₂O₂N₂:Eu can be obtained bymixing and calcination (P7). The reaction formula of the oxynitridephosphor by the calcination is shown in Formula 4.((1−2a)/3)Sr₃N₂+((2+3a)/6)Si₃N₄+((2−3a)/2)SiO₂+aEu₂O₃→Sr_((1-2a))EU_(2a)Si₂O₂N₂+N_(2a/3)  [Formula4]

However, the composition is a typical composition deduced by thecompounding ratio, and has adequate properties which are sufficientlyworthwhile for practical use, around the ratio. Further, the compositionof the objective phosphors can be changed by changing the compoundingratio of the respective raw materials.

The calcination temperature is not specifically limited. The calcinationis preferably carried out at a temperature of 1200 to 2000° C., and acalcination temperature of 1400 to 2000° C. is more preferable. It ispreferable to carry out the calcination of the raw materials of thephosphor 11 using a crucible made of boron nitride (BN) material and aboat. A crucible made of alumina (Al₂O₃) material can be also used inaddition to the crucible made of the boron nitride material.

Further, the calcination is preferably carried out in reductiveatmosphere. The reductive atmosphere is inactive gas atmospheres such asnitrogen atmosphere, nitrogen-hydrogen atmosphere, ammonia atmosphereand argon atmosphere, etc.

The objective oxynitride phosphor can be obtained by using the aboveproduction process.

Further, the oxynitride phosphor represented bySr_(X)Si_(Y)B_(T)O_(Z)N_(((2/3)X+Y+T−(2/3)Z−α)):Eu which contains B canbe produced as below.

A B compound, H₃BO₃ is preliminarily mixed with the oxide of Eu in drycondition. Europium oxide is used as the Eu compound, but metaleuropium, europium nitride and the like can be also used in like manneras the fore-mentioned other constitution elements. Additionally, animide compound, a amide compound and the like can be used as the Eu of araw material. Europium oxide is preferably those having high purity, butthose commercially available can be also used. A B compound is mixed ina dry process but a wet mixing can be also carried out.

The production process of the oxynitride phosphor is illustratedexemplifying the B compound H₃BO₃. However, there are Li, K, Na and thelike as the component constituting elements other than B, and as thesecompounds, for example, there can be used LiOH.H₂O, Na₂CO₃, K₂CO₃, RbCl,CsCl, Mg(NO₃)₂, CaCl₂.6H₂O, SrCl₂.6H₂O, BaCl₂.2H₂O, TiOSO₄.H₂O,ZrO(NO₃)₂, HfCl₄, MnO₂, ReCl₅, Cu(CH₃COO)₂.H₂O, AgNO₃, HAuCl₄.4H₂O,Zn(NO₃)₂.6H₂O, GeO₂, Sn(CH₃COO)₂ and the like.

A mixture of Eu and B is crushed. The mean particle diameter of themixture of Eu and B after the crushing is preferably about 0.1 μm to 15μm.

After carrying out the above-mentioned crushing, the nitride of Sr, thenitride of Si, the oxide of Si, and the oxide of Eu containing B aremixed in like manner as the fore-mentioned production steps ofSrSi₂O₂N₂:Eu. After said mixing, calcination is carried out and theobjective oxynitride phosphor can be obtained.

Embodiment 6

The phosphor of Embodiment 6 related to the present invention relates toan oxynitride phosphor which is suitable for being used in combinationwith a light-emitting element, in particular, a nitride semiconductorelement, and the phosphor is a phosphor in which Ba, Si and Eu areessential in the oxynitride phosphor of Embodiment 1.

Namely, the oxynitride phosphor related to Embodiment 6 uses at leastone or more of rare earth elements in which Eu is essential as anactivator, and contains at least one or more of Group II elementsselected from the group consisting of Ca, Sr, Ba and Zn in which Ba isessential, and at least one or more of Group IV elements selected fromthe group consisting of C, Si, Ge, Sn, Ti, Zr and Hf in which Si isessential. The combination of said elements is arbitrary but thephosphor having the composition below is preferable.

The oxynitride phosphor of Embodiment 6 is represented by the generalformula of L_(X)M_(Y)O_(Z)N_(((2/3)X+(4/3)Y−(2/3)Z)):R, orL_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+(4/3)Y+T−(2/3)Z)):R (wherein L is atleast one or more of Group II elements selected from the groupconsisting of Ca, Sr, Ba and Zn in which Ba is essential. M is at leastone or more of Group IV elements selected from the group consisting ofC, Si, Ge, Sn, Ti, Zr and Hf in which Si is essential. Q is at least oneor more of Group III elements selected from the group consisting of B,Al, Ga and In. O is an oxygen element. N is a nitrogen element. R is atleast one or more of rare earth elements in which Eu is essential.).Further, the phosphor of Embodiment 6 exhibits high brightness withinranges of 0.5<X<1.5, 1.5<Y<2.5, 0<T<0.5, and 1.5<Z<2.5 in like manner asEmbodiment 1. Further, among the general formula, the fore-mentioned X,the fore-mentioned Y and the fore-mentioned Z are preferably 0.8<X<1.2,1.8<Y<2.2, 0<T<0.5, and 1.7<Z<2.2, and in particular, the oxynitridephosphor in which the fore-mentioned X, the fore-mentioned Y and thefore-mentioned Z are represented by X=1, Y=2, and Z=2 is preferablebecause it exhibits high brightness. However, the present invention isnot limited to the above-mentioned ranges. Specifically, as theoxynitride phosphor of Embodiment 6, there are mentionedBaSi_(1.8)Ge_(0.2)O₂N₂:Eu, BaSi_(1.9)Ge_(0.1)O₂N₂:Eu,BaSi_(1.8)C_(0.2)O₂N₂:Eu, BaSi_(1.9)O_(0.1)O₂N₂:Eu,BaSi_(1.8)Ti_(0.2)O₂N₂:Eu, BaSi_(1.9)Ti_(0.1)O₂N₂:Eu,BaSi_(1.8)Sn_(0.2)O₂N₂:Eu, BaSi_(1.9)Sn_(0.1)O₂N₂:Eu,Ba_(0.9)Ca_(0.1)Si₂O₂N₂:Eu, Ba_(0.9)Sr_(0.1)Si₂O₂N₂:Eu,Ba_(0.9)Zn_(0.1)Si₂O₂N₂:Eu, Ba_(0.9)Ca_(0.1)Si_(1.8)Ge_(0.2)O₂N₂:Eu,Ba_(0.9)Sr_(0.1)Si_(1.8)Ge_(0.2)O₂N₂:Eu and the like.

Further, the present oxynitride phosphor can adjust the color tone andbrightness by changing a ratio of O to N in like manner as Embodiment 1.Further, the luminescence spectrum and intensity can be finely adjustedalso by changing a molar ratio of cation to anion which is shown by(L+M)/(O+N). This can be carried out, for example, by carrying outtreatment such as vacuum and removing N and O, but the present inventionis not limited to these processes. In the composition of the oxynitridephosphor, there may be contained at least one or more of Li, Na, K, Rb,Cs, Mn, Re, Cu, Ag and Au. The brightness and luminescence efficiencysuch as quantum efficiency can be adjusted by adding these. Further,other elements may be contained so far as the properties are notdamaged.

L is at least one or more of Group II elements selected from the groupconsisting of Be, Mg, Ca, Sr, Ba and Zn in which Ba is essential.Namely, Ba may be used alone, but various combinations such as Ba andCa, Ba and Sr, and Ba, Ca and Sr can be changed. The mixture of Group IIelements can vary the compounding ratio, if necessary.

M is at least one or more of Group IV elements selected from the groupconsisting of C, Si, Ge, Sn, Ti, Zr and Hf in which Si is essential. Mmay also use Si as a single body, and can change various combinationssuch as Si and Ge, and Si and C. Because the phosphor having goodcrystallinity and low cost can be provided using Si.

R is one or more of the rare earth elements in which Eu is essential.Specifically, the rare earth elements are La, Ce, Pr, Nd, Sm, Eu, Gd,Tb, Dy, Ho, Er, Tm, Yb and Lu. Eu may be used alone among these rareearth elements, but those containing Eu and at least one or more ofelements selected from the rare earth elements can be also used. Becauseelements other than Eu act as a co-activator. As R, Eu is preferablycontained by 70% by weight or more. In particular, R is a molar ratio ofGroup II element: R=1:0.005 to 1:0.15.

Europium Eu being the rare earth element is used as a luminescencecenter. The present invention is illustrated using only Eu, but is notlimited to this, and those which were co-augmented with Eu can be used.Europium has mainly a divalent and trivalent energy levels. The phosphorof the present invention uses Eu²⁺ as the activator for an alkali earthmetal silicone nitride being the mother body. Eu²⁺ is easily oxidizedand commercially available as the composition of trivalent Eu₂O₃ ingeneral.

L and M of the main components can be also used as respective compoundsthereof as the mother material. These L and M of the main components canbe used as metals, oxides, imides, amides, nitrides, and various salts.Further, the elements of L and M of the main components may bepreliminarily mixed to be used.

Q is at least one of more of Group III elements selected from the groupconsisting of B, Al, Ga and In. Q is also used as metals, oxides,imides, amides, nitrides, and various salts. For example, they are B₂O₆,H₃BO₃, Al₂O₃, Al(NO₃)₃.9H₂O, AlN, GaCl₃, InCl₃ and the like.

The oxynitride phosphor of Embodiment 6 can be prepared as below.

Firstly, the nitride of L, the nitride of M and the oxide of M are mixedas the mother body materials. The oxide of Eu is mixed with said motherbody materials as the activator. These are weighed so as to be thedesired amount, and mixed until being homogeneous. In particular, thenitride of L, the nitride of M and the oxide of M in said mother bodymaterials are preferably mixed at molar ratios of 0.5< the nitride ofL<1.5, 0.25< the nitride of M<1.75, and 2.25< the oxide of M<3.75. Thefixed amounts of these mother body materials are weighed and mixed so asto be the composition ratio of L_(X)M_(Y)O_(Z)N_(((2/3)X+Y−(2/3)Z−α)):Ror L_(X)M_(Y)Q_(T)O_(Z)N_(((2/3)X+Y+T−(2/3)Z−α)):R.

(Example of More Specific Production Process of Oxynitride Phosphor ofEmbodiment 6)

Then, the production process of the oxynitride phosphor, BaSi₂O₂N₂:Eurelated to Embodiment 6 is illustrated, but the present invention is notlimited to the production processes below. FIG. 62 is a process chartshowing the production process of the oxynitride phosphor of Embodiment6.

Firstly, in the present process, the nitride of Ba, the nitride of Si,the oxide of Si and the oxide of Eu are prepared. As these rawmaterials, those purified are preferably used, but those commerciallyavailable may be used.

1. Nitride of Ba

Ba₃N₂ is used as the nitride of Ba of a raw material. Compounds such asan imide compound, an amide compound and BaO can be also used as the rawmaterial, and the single body of Ba can be also used. Further, the Ba ofa raw material may be those containing B, Ga and the like.

The nitride of Ba, Ba₃N₂, is crushed (P1).

2. Nitride of Si

Si₃N₄ is used as the nitride of Si of a raw material. As the rawmaterial, a nitride compound, an imide compound, an amide compound andthe like can be also used, and the single body of Si can be also used.For example, they are Si₃N₄, Si(NH₂)₂, Mg₂Si, Ca₂Si, SiC and the like.The purity of the Si of a raw material is preferably 3N or more, but B,Ga and the like may be contained.

The nitride of Si, Si₃N₄, is crushed (P2).

3. Oxide of Si

SiO₂ is used as the oxide of Si of a raw material. Hereat, those whichare commercially available are used (Silicon Dioxide 99.9%, 190-09072,manufactured by Wako Pure Chemicals Industries, Ltd.).

The oxide of Si, SiO₂, is crushed (P3).

4. Oxide of Eu

Eu₂O₃ is used as the oxide of Eu of a raw material. As the raw material,a nitride compound, an imide compound, an amide compound and the likecan be also used, and the single body of Eu can be also used. Europiumnitride other than europium oxide is preferably used. Because oxygen ornitrogen is contained in a product.

The oxide of Eu, Eu₂O₃, is crushed (P4).

The above-mentioned nitride of Ba, Ba₃N₂, which was crushed, the nitrideof Si, Si₃N₄, the oxide of Si, SiO₂, and the oxide of Eu, Eu₂O₃ areweighed and mixed (P5). The above-mentioned raw materials are weighed soas to be a fixed compounding ratio.

Then, the mixture of the nitride of Ba, the nitride of Si, the oxide ofSi, and the oxide of Eu is calcined (P6). Said mixture is charged in acrucible to be calcined.

The oxynitride phosphor represented by BaSi₂O₂N₂:Eu can be obtained bymixing and calcination (P7). The reaction formula of the basicconstituting elements by the calcination is shown in Formula 5.(1/3)Ba₃N₂+(1/3)Si₃N₄+SiO₂+aEu₂O₃→BaSi₂O₂N₂:Eu   [Formula 5]

However, the composition is a typical composition deduced from thecompounding ratio, and has adequate properties which are worthwhile forpractical use, around the ratio. Further, the composition of theobjective phosphors can be changed by changing the compounding ratio ofthe respective raw materials.

The calcination temperature is not specifically limited. The calcinationis preferably carried out at a temperature of 1200 to 1700° C., and acalcination temperature of 1400 to 1700° C. is more preferable. It ispreferable to carryout the calcination of the raw materials of thephosphor 11 using a crucible made of boron nitride (BN) material and aboat. A crucible made of alumina (Al₂O₃) material can be also used inaddition to the crucible made of boron nitride material.

Further, the calcination is preferably carried out in reductiveatmosphere. The reductive atmosphere is inactive gas atmospheres such asnitrogen atmosphere, nitrogen-hydrogen atmosphere, ammonia atmosphereand argon atmosphere, etc.

The objective oxynitride phosphor of Embodiment 6 can be obtained byusing the above production process.

Further, the oxynitride phosphor represented byBa_(X)Si_(Y)B_(T)O_(Z)N_(((2/3)X+Y+T−(2/3)Z−α)):Eu can be produced asbelow.

An Eu oxide is preliminarily mixed with a B compound, H₃BO₃ in drycondition. Europium oxide is used as the Eu compound, but metaleuropium, europium nitride and the like can be also used in like manneras the fore-mentioned other constitution elements. Additionally, animide compound, an amide compound and the like can be used as the Eucompound. Europium oxide is preferably those having high purity, butthose commercially available can be also used. A B compound is mixed ina dry process but a wet mixing can be also carried out.

The production process of the oxynitride phosphor is illustratedexemplifying the B compound H₃BO₃. However, there are Li, K, Na and thelike as the component constituting elements other than B, and as thesecompounds, for example, there can be used LiOH.H₂O, Na₂CO₃, K₂CO₃, RbCl,CsCl, Mg(NO₃)₂, CaCl₂.6H₂O, SrCl₂.6H₂O, BaCl₂.2H₂O, TiOSO₄.H₂O,ZrO(NO₃)₂, HfCl₄, MnO₂, ReCl₅, Cu(CH₃COO)₂.H₂O, AgNO₃, HAuCl₄.4H₂O,Zn(NO₃)₂.6H₂O, GeO₂, Sn(CH₃COO)₂ and the like.

A mixture of Eu and B is crushed. The mean particle diameter of themixture of Eu and B after the crushing is preferably about 0.1 μm to 15μm.

After the above-mentioned crushing, the nitride of Ba, the nitride ofSi, the oxide of Si, and the oxide of Eu containing B are mixed in likemanner as the fore-mentioned production steps of BaSi₂O₂N₂:Eu. Aftersaid mixing, calcination is carried out and the objective oxynitridephosphor can be obtained.

The above oxynitride phosphors of Embodiment 6 which are constitutedabove have stability equal to or more than a YAG-base phosphor, andfurther have the similar action and effect as Embodiment 1.

Further, the oxynitride phosphors of Embodiment 6 can select thecomposition and composition ratio so as to have the luminescencespectrum which has the luminescence peak in a blue green region to agreen region, can realize high luminescence brightness and luminescenceefficiency within the range in particular, and can widely adjust thecolor tone, quantum efficiency and the like.

EXAMPLES

The phosphors and the light-emitting device related to the presentinvention are illustrated below according to examples, but not limitedto these examples.

Further, temperature properties are shown by a relative brightness inwhich the luminescence brightness at 25° C. is 100%. Further, theparticle diameter shows the fore-mentioned particle diameter, and is avalue obtained by an air transmission process called as F.S.S.S. No.(Fisher Sub Sieve Sizer's No.).

Examples 1 to 27 are examples related to the oxynitride phosphor relatedto Embodiment 1.

Examples 1 to 5

Table 1 shows the properties of the oxynitride phosphors of Examples 1to 5 related to the present invention.

Further, FIG. 3 is a chart showing luminescence spectra when the nitridephosphors of Examples 1 to 5 were excited at Ex=400 nm. FIG. 4 is achart showing the luminescence spectra when the oxynitride phosphors ofExamples 1 to 5 were excited at Ex=460 nm. FIG. 5 is a chart showing theexcitation spectra of the oxynitride phosphors of Examples 1 to 5. FIG.6 is a chart showing the reflection spectra of the oxynitride phosphorsof Examples 1 to 5. FIG. 7 is an SEM (scanning electron microscope)photo photographing the oxynitride phosphor of Example 1. Hereat, thename of a color and chromaticity are according to JIS Z8110.

TABLE 1 Ex = 400 nm Peak Particle Color tone Color tone wavelengthdiameter X Y (nm) (μm) Example 1 0.434 0.543 561 3.5 Example 2 0.4330.543 561 4.0 Example 3 0.349 0.608 539 4.0 Example 4 0.352 0.604 5393.5 Example 5 0.182 0.55 509 3.5 Ex = 460 nm Peak Color tone Color tonewavelength X Y (nm) Example 1 0.437 0.545 564 Example 2 0.434 0.546 564Example 3 0.347 0.616 540 Example 4 0.351 0.614 540 Example 5 0.2140.623 510

Example 1 is the oxynitride phosphor represented by CaSi₂O₂N₂:Eu.Example 2 is the oxynitride phosphor represented byCa_(0.90)Mg_(0.10)Si₂O₂N₂:Eu. Example 3 is the oxynitride phosphorrepresented by SrSi₂O₂N₂:Eu. Example 4 is the oxynitride phosphorrepresented by Sr_(0.90)Mg_(0.10)Si₂O₂N₂:Eu. Example 5 is the oxynitridephosphor represented by BaSi₂O₂N₂:Eu.

In Examples 1 to 5, Ca₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were used as the rawmaterials, and after crushing these raw materials at 0.1 to 3.0 μm,treatment was respectively carried out below.

Example 1

Firstly, compounds are weighed below.

-   Ca₃N₂:6.01 g-   Si₃N₄:5.99 g-   SiO₂:7.36 g-   Eu₂O₃:0.66 g

After weighing the above-mentioned amounts, Ca₃N₂, Si₃N₄, SiO₂ and Eu₂O₃were mixed under nitrogen atmosphere in a glove box until uniformity.The concentration of Eu is 0.43% by mol in Examples 1 to 5.

In Example 1, the mix ratio (molar ratio) of the raw materials isCa₃N₂:Si₃N₄:SiO₂:Eu₂O₃=1:0.51:3.02:0.046. 6.01 g of Ca₃N₂ (molecularweight=148.3), 5.99 g of Si₃N₄ (molecular weight=140.3), 7.36 g of SiO₂(molecular weight=60.09) and 0.66 g of Eu₂O₃ (molecular weight=352.0)were weighed so as to be the mixing ratio, and mixed.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1500° C. for about 5 hours.

The objective oxynitride phosphor was obtained thereby. The theoreticalcomposition of the oxynitride phosphor obtained is CaSi₂O₂N₂:Eu.

When the % by weight of O and N in the oxynitride phosphor of Example 1was measured, O and N were contained by 19.3% by weight and 14.5% byweight respectively. The weight ratio of O to N is O:N=1:0.75.

The calcination of the oxynitride phosphor related to Examples iscarried out in ammonia atmosphere using a boron nitride crucible. Acrucible made of a metal is not preferably used for the crucible. Whenthe crucible made of a metal is used, it is considered that the crucibleis eroded and it causes the lowering of luminescence properties.Accordingly, it is preferable to use a crucible made of ceramics such asalumina.

Example 2 is the oxynitride phosphor in which the portion of Ca wassubstituted with Mg. Example 2 used magnesium nitride, Mg₃N₂ (MG102PB98%, manufactured by High Purity Chemicals Co.) (molecularweight=101.0), and the under-mentioned amounts of crushed powders wereweighed so that the mixing ratio (molar ratio) of the raw materials isCa₃N₂:Mg₃N₂:Si₃N₄:SiO₂:Eu₂O₃=1:0.12:0.57:3.37:0.052.

-   Ca₃N₂:5.44 g-   Mg₃N₂:0.43 g-   Si₃N₄:6.05 g-   SiO₂:7.43 g-   Eu₂O₃:0.67 g

Further, said raw materials were mixed and calcination was carried outunder the same conditions as Example 1.

Example 3 is the oxynitride phosphor in which Ca of Example 1 wassubstituted with Sr. Example 3 used strontium nitride, Sr₃N₄ (molecularweight=290.9), and the under-mentioned amounts of crushed powders wereweighed so that the mixing ratio (molar ratio) of the raw materials isSr₃N₂:Si₃N₄:SiO₂:Eu₂O₃=1:0.51:3.02:0.046.

-   Sr₃N₂:9.14 g-   Si₃N₄:4.65 g-   SiO₂:5.71 g-   Eu₂O₃:0.51 g

Example 3 mixed said raw materials were mixed and carried outcalcination under the same conditions as Example 1.

When the % by weight of O and N in the oxynitride phosphor of Example 3was measured, O and N were contained by 15.3% by weight and 11.2% byweight respectively in the total amount. The weight ratio of O to N isO:N=1:0.73.

Example 4 is the oxynitride phosphor in which Ca of Example 2 wassubstituted with Sr. In Example 4, the under-mentioned amounts ofcrushed powders were weighed so that the mixing ratio (molar ratio) ofthe raw materials isSr₃N₂:Mg₃N₂:Si₃N₄:SiO₂:Eu₂O₃=1:0.12:0.57:3.37:0.052.

-   Sr₃N₂:8.46 g-   Mg₃N₂:0.34 g-   Si₃N₄:4.80 g-   SiO₂:5.89 g-   Eu₂O₃:0.53 g

Said raw materials were mixed and calcination was carried out under thesame conditions as Example 1.

Example 5 is the oxynitride phosphor in which Ca of Example 1 wassubstituted with Ba. Example 5 used barium nitride, Ba₃N₂ (molecularweight=316.6), and the under-mentioned amounts of crushed powders wereweighed so that the mixing ratio (molar ratio) of the raw materials isBa₃N₂:Si₃N₄:SiO₂:Eu₂O₃=1:0.76:0.22:0.033.

-   Ba₃N₂:11.2 g-   Si₃N₄:3.77 g-   SiO₂:4.63 g-   Eu₂O₃:0.42 g

Said raw materials were mixed and calcination was carried out under thesame conditions as Example 1.

Any of the calcined products of Examples 1 to 5 is crystalline powder orparticles. The particle diameter was about 1 to 5 μm.

The measurement of the excitation spectra of the oxynitride phosphors ofExamples 1 to 5 was carried out. As a result of the measurement, theyare strongly excited at a shorter wavelength side than 490 nm.

The oxynitride phosphors of Examples 1 to 5 were excited by Ex=460 nm.Since Ex=460 nm is a wavelength often used in a blue light-emittingelement, excitation was carried out at said wavelength region. As aresult, the oxynitride phosphor of Example 1 has a luminescence color ata yellow region of color tone, x=0.437 and color tone y=0.545. Theoxynitride phosphor of Example 4 has a luminescence color at a yellowregion of color tone, x=0.351 and color tone, y=0.614. Any of theoxynitride phosphors of Examples 1 to 5 exhibited higher luminescenceefficiency than a conventional phosphor.

The oxynitride phosphors of Examples 1 to 5 were excited by Ex=400 nm.The oxynitride phosphor of Example 1 has a luminescence color at ayellow green region of color tone, x=0.434 and color tone, y=0.543. Theoxynitride phosphor of Example 3 has a luminescence color at a yellowgreen region of color tone, x=0.349 and color tone, y=0.608. Any of theoxynitride phosphors of Examples 1 to 5 exhibited higher luminescenceefficiency than a conventional phosphor.

Further, temperature properties were excellent. The temperatureproperties are shown by relative brightness in which luminescencebrightness at 25° C. is 100%. The particle diameter is a value accordingto an air transmission process called F.S.S. No. (Fisher Sub SieveSizer's No.). The temperature properties of Examples 1 to 5 are 95 to100% at 100° C. They were 65 to 90% at 200° C.

When the X-ray diffraction images of the above-mentioned theseoxynitride phosphors were measured, any image shows a sharp diffractionpeak, and it was cleared that the phosphors obtained were crystallinecompounds having regularity.

Examples 6 to 15

Table 2 shows the properties of Examples 6 to 15 of the oxynitridephosphors related to the present invention.

Further, FIG. 8 is a chart showing the luminescence spectra when theoxynitride phosphors of Examples 6 to 10 were excited at Ex=400 nm. FIG.9 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 6 to 10 were excited at Ex=460 nm. FIG. 10 is achart showing the luminescence spectra when the oxynitride phosphors ofExamples 11 to 15 were excited at Ex=400 nm. FIG. 11 is a chart showingthe luminescence spectra when the oxynitride phosphors of Examples 11 to15 were excited at Ex=460 nm. FIG. 12 is a chart showing the excitationspectra of the oxynitride phosphors of Examples 11 to 15. FIG. 13 is achart showing the reflection spectra of the oxynitride phosphors ofExamples 11 to 15.

TABLE 2 Sr/Ca Luminescence Luminescence Quantum Molar peak wavelengthColor tone Color tone brightness efficiency ratio (nm) x y (%) (%)Excitation at Ex = 400 nm Example 6  0/10 561 0.434 0.543 100.0 100.0Example 7 3/7 543 0.388 0.570 111.0 106.3 Example 8 5/5 546 0.375 0.579135.9 128.6 Example 9 7/3 544 0.372 0.593 148.0 131.8 Example 10 10/0 539 0.349 0.608 145.8 127.3 Excitation at Ex = 460 nm Example 6  0/10564 0.437 0.545 100.0 100.0 Example 7 3/7 549 0.391 0.578 109.4 103.1Example 8 5/5 545 0.378 0.588 125.4 116.9 Example 9 7/3 545 0.371 0.600162.8 142.7 Example 10 10/0  540 0.347 0.616 138.8 119.2 Excitation atEx = 400 nm Example 11 6/4 542 0.366 0.593 124.4 128.1 Example 12 7/3541 0.366 0.595 133.3 135.8 Example 13 8/2 542 0.363 0.599 142.0 143.4Example 14 9/1 540 0.353 0.605 122.7 123.2 Example 15 10/0  540 0.3420.611 100.0 100.0 Excitation at Ex = 460 nm Example 11 6/4 542 0.3650.603 134.5 137.8 Example 12 7/3 542 0.364 0.605 148.5 151.1 Example 138/2 542 0.360 0.609 156.8 158.4 Example 14 9/1 541 0.351 0.615 125.9126.8 Example 15 10/0  539 0.339 0.622 100.0 100.0

Examples 6 to 10 are the oxynitride phosphors represented bySr_(X)Ca_((1−X))Si₂O₂N₂:Eu (0≦X≦1), and carry out production changing amolar ratio of Sr to Ca.

Examples 6 to 10 carried out the production of the oxynitride phosphorsunder almost the same condition as Example 1. Sr₃N₂, Ca₃N₂, Si₃N₄, SiO₂and Eu₂O₃ were used as raw materials. After weighing the fixed amountsof said raw materials, Sr₃N₂, Ca₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were mixedunder nitrogen atmosphere in a glove box until uniformity. Theconcentration of Eu is 0.43% by mol in Examples 6 to 15.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1450° C. for about 5 hours.

The objective oxynitride phosphor was obtained thereby.

The luminescence brightness and quantum efficiency of Examples 6 to 10are represented with a relative value on the basis of Example 6.

From this result, when Examples 6 to 10 are exited by a light sourcenearby 400 nm, the phosphors mixing Sr and Ca exhibited higherluminescence brightness and quantum efficiency than those using only Ca.On the other hand, when Example 6 to 10 are exited by a light sourcenearby 460 nm, the phosphor of Sr:Ca=7:3 exhibited the highestluminescence efficiency. Further, the luminescence efficiency can beimproved by substituting the portion of ca and increasing Sr. Further,the color tone can be changed by changing a molar ratio of Sr to Ca.

Examples 11 to 15 are the oxynitride phosphors represented bySr_(X)Ca_((10−X))Si₂O₂N₂:Eu (0≦X≦1), and carry out production changing amolar ratio of Sr to Ca.

Examples 11 to 15 carried out the production of the oxynitride phosphorsunder almost the same condition as Example 1. Sr₃N₂, Ca₃N₂, Si₃N₄, SiO₂and Eu₂O₃ were used as raw materials. After weighing the fixed amountsof said raw materials, Sr₃N₂, Ca₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were mixedunder nitrogen atmosphere in a glove box until uniformity. Theconcentration of Eu is 0.43% by mol in Examples 6 to 15.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1550° C. for about 5 hours.

The objective oxynitride phosphor was obtained thereby.

The luminescence brightness and quantum efficiency of Examples 11 to 15are represented with a relative value on the basis of Example 15.

From this result, when Examples 11 to 15 are exited by a light sourcenearby 400 nm, the phosphors mixing Sr and Ca exhibited higherluminescence brightness and quantum efficiency than those using only Sr.Further, when a molar ratio of Sr:Ca is Sr:Ca=6:4 to 9:1, theluminescence efficiency can be improved. In particular, the high valuesof luminescence brightness and quantum efficiency are exhibited in caseof Sr:Ca=7:3 to 8:2. Further, the color tone can be changed by changingthe molar ratio of Sr to Ca.

Examples 16 to 20

Table 3 shows the properties of Examples 10, 16 to 20 of the oxynitridephosphors related to the present invention.

Further, FIG. 14 is a chart showing the luminescence spectra when theoxynitride phosphors of Examples 10 and 16 to 20 were excited at Ex=400nm. FIG. 15 is a chart showing the luminescence spectra when theoxynitride phosphors of Examples 10 and 16 to 20 were excited at Ex=460nm. FIG. 16 is a chart showing the excitation spectra of the oxynitridephosphors of Examples 10 and 16 to 20. FIG. 17 is a chart showing thereflection spectra of the oxynitride phosphors of Examples 10 and 16 to20.

TABLE 3 Sr/Ba Luminescence peak Luminescence Quantum Molar wavelengthColor tone Color tone brightness efficiency ratio (nm) x y (%) (%)Excitation at Ex = 400 nm Example 10 10/0  539 0.349 0.608 100.0 100.0Example 16 8/2 549 0.388 0.581 84.3 86.6 Example 17 6/4 556 0.404 0.55677.5 83.2 Example 18 4/6 553 0.411 0.552 36.1 40.9 Example 19 2/8 5240.269 0.595 19.9 22.5 Example 20  0/10 496 0.142 0.464 25.9 45.8Excitation at Ex = 460 nm Example 10 10/0  540 0.347 0.616 100.0 100.0Example 16 8/2 548 0.386 0.590 95.8 97.8 Example 17 6/4 558 0.408 0.57187.6 92.7 Example 18 4/6 558 0.417 0.559 47.4 53.5 Example 19 2/8 5270.293 0.621 13.6 15.2 Example 20  0/10 497 0.120 0.532 37.8 64.2

Examples 10, 16 to 20 are the oxynitride phosphors represented bySr_(X)Ba_((1−X))Si₂O₂N₂:Eu (0≦X≦1), and carry out production changing amolar ratio of Sr to Ba.

Examples 10, 16 to 20 carried out the production of the oxynitridephosphors under almost the same condition as Example 1. Sr₃N₂, Ba₃N₂,Si₃N₄, SiO₂ and Eu₂O₃ were used as raw materials. After weighing thefixed amounts of said raw materials, Sr₃N₂, Ba₃N₂, Si₃N₄, SiO₂ and Eu₂O₃were mixed under nitrogen atmosphere in a glove box until uniformity.The concentration of Eu is 0.43% by mol in Examples 10, 16 to 20.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1450° C. for about 5 hours.

The objective oxynitride phosphors were obtained thereby.

The luminescence brightness and quantum efficiency of Examples 10, 16 to20 are represented with a relative value on the basis of Example 10.

From this result, when Examples 10, 16 to 20 are exited by a lightsource nearby 400 nm and 460 nm, the phosphors being mixed at Sr:Ba=6:4to 8:2 exhibited higher luminescence brightness and quantum efficiencythan those being mixed at Sr:Ba=2:8. Further, the luminescenceefficiency can be improved by substituting the portion of Ba andincreasing Sr. Further, the color tone can be changed by changing amolar ratio of Sr to Ba. Further, the BaSi₂N₂O₂:Eu of Example 20 has theluminescence peak wavelength nearby 496 nm and exhibits the highluminescence efficiency. The color rendering of the white light-emittingdevice can be improved by using the oxynitride phosphor related toExample 20.

Examples 21 to 24

Table 4 shows the properties of Examples 21 to 24 of the oxynitridephosphors related to the present invention.

Further, FIG. 18 is a chart showing the luminescence spectra when theoxynitride phosphors of Examples 21 to 24 were excited at Ex=400 nm.FIG. 19 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 21 to 24 were excited at Ex=460 nm. FIG. 20 is achart showing the excitation spectra of the oxynitride phosphors ofExamples 21 to 24. FIG. 21 is a chart showing the reflection spectra ofthe oxynitride phosphors of Examples 21 to 24.

TABLE 4 Ca/Ba Luminescence peak Luminescence Quantum Molar wavelengthColor tone Color tone brightness efficiency ratio (nm) x y (%) (%)Excitation at Ex = 400 nm Example 21 8/2 570 0.456 0.502 100.0 100.0Example 22 6/4 593 0.508 0.462 54.5 63.2 Example 23 4/6 542 0.353 0.42542.6 52.1 Example 24 2/8 493 0.254 0.389 56.4 69.2 Excitation at Ex =460 nm Example 21 8/2 570 0.456 0.502 100.0 100.0 Example 22 6/4 5930.508 0.462 54.5 63.2 Example 23 4/6 542 0.353 0.425 42.6 52.1 Example24 2/8 493 0.254 0.389 56.4 69.2

Examples 21 to 24 are the oxynitride phosphors represented byCa_(X)Ba_((1−X))Si₂O₂N₂:Eu (0≦X≦1), and carry out production changing amolar ratio of Ca to Ba.

Examples 21 to 24 carried out the production of the oxynitride phosphorsunder almost the same condition as Example 1. Ca₃N₂, Ba₃N₂, Si₃N₄, SiO₂and Eu₂O₃ were used as raw materials. After weighing the fixed amountsof said raw materials, Ca₃N₂, Ba₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were mixedunder nitrogen atmosphere in a glove box until uniformity. Theconcentration of Eu is 0.43% by mol in Examples 21 to 24.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1450° C. for about 5 hours.

The objective oxynitride phosphors were obtained thereby.

The luminescence brightness and quantum efficiency of Examples 21 to 24are represented with a relative value on the basis of Example 21.

From this result, when Examples 21 to 24 are exited by a light sourcenearby 400 nm, the phosphors being mixed at Ca:Ba=8:2 exhibited higherluminescence brightness and quantum efficiency than those being mixed atCa:Ba=4:6. On the other hand, when Examples 21 to 24 are excited by alight source nearby 460 nm, the phosphor being mixed at Ca:Ba=8:2exhibited the higher luminescence brightness and quantum efficiency thanthat being mixed at Ca:Ba=2:8. Further, the color tone can be changed bychanging the molar ratio of Ca to Ba.

Examples 25 to 27

The structural analysis of the oxynitride phosphors of Examples 25 to 27was carried out. The composition of Example 25 is CaSi₂O₂N₂. Thecomposition of Example 26 is SrSi₂O₂N₂. The composition of Example 27 isBaSi₂O₂N₂. FIG. 22 is a schematic view showing the rhombic system. FIG.23 is a chart showing the X-ray diffraction pattern of the oxynitridephosphor of Example 25. FIG. 24 is a chart showing the X-ray diffractionpattern of the oxynitride phosphor of Example 26. FIG. 25 is a chartshowing the X-ray diffraction pattern of the oxynitride phosphor ofExample 27.

From this result, the unit lattice of crystals of the oxynitridephosphor is attributed to the rhombic system. The rhombic system isa≠b≠c and α=β=γ=90°, and has 3 of mutually perpendicular diads or twosymmetry planes which cross with the diad.

Example 28 Light-Emitting Device

The light-emitting device of Example 28 (FIG. 1) was produced using theabove-mentioned oxynitride phosphor. As the phosphor, CaSi₂O₂N₂:Eu ofExample 1, Ca₂Si₅N₈:Eu and (Ca_(0.93), Eu_(0.05), Mn_(0.02))₁₀(PO₄)₆Cl₂are used. FIG. 26 is a plane view showing the light-emitting elementrelated to the present invention. FIG. 27 is a section view showing theA-A′ of the light-emitting element related to the present invention.FIG. 28 is a chart showing the luminescence spectrum of thelight-emitting device of Example 28 related to the present invention.FIG. 29 is a chart showing the chromaticity coordinate of thelight-emitting device of Example 28 related to the present invention.

The light-emitting element of Example 28 is specifically illustrated.

(Light-Emitting Element)

The substrate 201 comprising sapphire (c plane) was set in the reactionvessel of MOVPE, and the temperature of the substrate 201 was raiseduntil about 1050° C. while flowing hydrogen to clean the substrate 201.

Wherein a sapphire substrate is used for the substrate 201 in thepresent Example 28, but there may be used different kind substratesdifferent from a nitride semiconductor substrate, namely nitridesemiconductor substrates such as AlN, AlGaN and GaN, as the substrate201. As the different kind substrates, for example, there can be usedinsulating substrate such as sapphire in which either of a C plane, Rplane and A plane is a main plane, and spinel (MgAl₂O₄); oxidesubstrates which lattice-coordinate with SiC (including 6H, 4H and 3C),ZnS, ZnO, GaAs, Si and a nitride semiconductor; substrate materialswhich can grow a nitride semiconductor and are different from thenitride semiconductor. As the preferable different kind substrates,sapphire and spinel are mentioned. Further, the different kindsubstrates may be off-angled, and in this case, when a substrate whichwas off-angled in a stepwise shape is used, the growth of the groundworklayer 202 comprising GaN is grown in good crystallinity, therefore it ispreferable. Further, when the different kind substrate is used, anitride semiconductor which becomes the groundwork layer 202 beforeformation of element structure is grown on the different kind substrate,then the different kind substrate is removed by processes such aspolishing, and an element structure may be formed as the single bodysubstrate of the nitride semiconductor. Further, there may be a processof removing the different kind substrate after forming the elementstructure. The substrate of the nitride semiconductor such as AlN may beused in addition to a GaN substrate.

(Buffer Layer)

Successively, the temperature of the substrate 201 is lowered to 510°C., and a buffer layer (not illustrated) comprising GaN is grown on thesubstrate 201 at a film thickness of about 100 angstroms using hydrogenas a carrier gas and ammonia and TMG (trimethylgallium) as the rawmaterial gases.

(Groundwork Layer)

After forming the buffer layer, only TMG is stopped, and the temperatureof the substrate 201 is raised to 1050° C. When it reached at 1050° C.,an undoped GaN layer is grown at a film thickness of 2 μm similarlyusing ammonia gas and TMG as the raw material gases.

(n-Type Layer)

Successively, an n-type layer 203 comprising GaN in which Si was dopedby 4.5×10¹⁸/cm³ is grown at a thickness of 3 μm at 1050° C. similarlyusing ammonia gas and TMG as the raw material gases and silane gas asimpurity gas, as a n-side contact layer which forms the n-side electrode211 a as the n type layer.

(Active Layer)

A barrier layer comprising Si-doped GaN is grown at a film thickness of50 angstroms, and successively, a well layer comprising undopedIn_(0.1)Ga_(0.7)N is grown at a film thickness of 50 angstroms at 800°C. using TMG, TMI and ammonia. Then, 4 layers of the barrier layer and 3layers of well layer are alternatively laminated in order ofbarrier+well+barrier+well . . . +barrier, and the active layer 204comprising a multiple quantum well structure having a total filmthickness of 350 angstroms is grown.

(p-Side Carrier Confining Layer)

Then, the p-side carrier confining layer 205 comprisingAl_(0.3)Ga_(0.7)N in which Mg was doped by 5×10¹⁹/cm³ is grown at a filmthickness of 100 angstroms using TMG, TMA, ammonia and Cp₂Mg(cyclopentadienylmagnesium).

(The First p-Layer)

Successively, the first p-layer 206 comprising GaN in which p-typeimpurities were doped is grown at a film thickness of 0.1 μm using TMG,ammonia and Cp₂Mg.

(The Second p-Layer)

As the second p-layer, a p-side contact layer 208 on whose surface ap-side electrode 210 is formed is formed. The p-side contact layer 208is obtained by growing a p-type GaN in which Mg was doped by 1×10²⁰/cm³on the current diffusion layer, at a film thickness of 150 angstroms.Since the p-side contact layer 208 is a layer on which the p-sideelectrode 210 is formed, it is preferably a high carrier concentrationwith 1×10¹⁷/cm³ or more. When it is lower than 1×10¹⁷/cm³, it is apt tobe difficult to obtain a preferable contact with the electrode. Further,when the composition of the contact layer is GaN, it is easy to obtain apreferable contact with the electrode material.

After completion of the reaction forming the above element structure,the temperature is lowered to room temperature, and annealing is carriedout at 700° C. charging a wafer in the reaction vessel under nitrogenatmosphere, and the resistance of the p-layer is further lowered. Thewafer on which the element structure was formed is taken out from theequipment, and an electrode forming step described below is carried out.

After the annealing, the wafer is taken out from the reaction vessel, afixed mask is formed on the surface of the p-side contact layer 208being the uppermost layer, etching is carried out from the p-sidecontact layer 208 side with an RIE (reactive ion etching) equipment toexpose the surface of the n-side contact layer, and an electrode formingsurface is formed.

As a p-side electrode 210, Ni and Au are laminated in order, and thep-side contact layer comprising Ni/Au is formed. Further, the p-sideelectrode 210 becomes an ohmic electrode which is brought in contactwith the second p-layer and the p-side contact layer 208. At this time,the electrode branch 210 a formed has a width of the stripe shapeluminescent portion 209 of about 5 μm and a width of the stripe shapeelectrode branch 210 of about 3 μm, and the stripe shape luminescentportion 209 and the stripe shape electrode branch 210 are alternatelyformed. Only the portion of the p-side electrode 210 is formed at aregion where the p-pat electrode is formed, and formed over the p-patelectrode to be electrically conducted. At this time, only the portionof the p-side electrode 210 is formed at a region where the p-patelectrode is formed, the p-pat pat electrode 210 b is formed on thesurface of the p-side contact layer 208, the portion is formed over thep-side electrode 210 to be electrically conducted. At this time, thereis obtained a structure in which the surface of the p-side contact layer208 where the p-side pat electrode 210 b is provided is not brought incontact with the p-side electrode 210 and the p-side contact layer 208,a shot key barrier is formed between both, current does not directly runin the element from the forming portion of the p-side pat electrode 210b, and current is injected in the inside of the element through theelectrode branch 210 a which was electrically connected.

Successively, an n-electrode 211 a is formed on the exposed plane 203 aon which the n-layer 203 was exposed. The n-electrode 211 a is formed bylaminating Ti and Al.

Here at, the n-electrode 211 a is an ohmic electrode which was broughtin ohmic contact with the exposed face 203 a of the n-type layer 203.After forming the p-side electrode 210 and the n-side electrode 211 afor ohmic, the respective electrodes are brought in ohmic contact bybeing annealed by heat treatment. The p-side ohmic electrode which wasobtained at this time becomes an opaque film which hardly transmit theluminescence of the active layer 204.

Successively, an insulation film comprising SiO₂ is formed on theportion or the whole surface excluding the whole of the above-mentionedp-side electrode 210 and the n-side electrode 211 a, namely, theinsulation film comprising SiO₂ is formed on the whole element surfacessuch as the exposed face 203 a of the n-type layer 203 and the side faceof said exposed face 203 a. After formation of the insulation film, thepat electrodes for bonding are respectively formed on the surfaces ofthe p-side electrode 210 and the n-side electrode 211 a which wereexposed from the insulation film, and electrically conducted with therespective electrodes for ohmic. The p-side pat electrode 210 b and then-side pat electrode 211 b are respectively formed by laminating Ni, Tiand Au on the respective electrodes for ohmic.

Finally, the light-emitting elements having a length of 300 μm at oneside are obtained by dividing the substrate 201.

The luminescence peak wavelength is about 400 nm.

The properties of the light-emitting device of Example 28 are shown inTable 5.

TABLE 5 Luminous Radiation intensity Peak analysis measurementwavelength Current Voltage Radiometric Photometric Peak If (mA) Vf (V)(mW) (lm) (nm) Light 20 3.4 6.2 1.84 464 emitting device Color Averagecolor Lamp Color Color temperature rendering efficiency tone x tone yTcp (K) Ra (lm/w) Light 0.356 0.368 4690 82.2 27.1 emitting device

The light-emitting device of Example 28 exhibits a luminescence color ata white region. The light-emitting device of Example 28 exhibits aluminescence spectrum having the luminescence peak wavelengths at 360 to430 nm, 430 to 500 nm and 500 to 730 nm. More specifically, it exhibitsa luminescence spectrum having the luminescence peak wavelengths at 390to 410 nm, 455 to 475 nm and 550 to 600 nm. The phosphors excited by thelight-emitting element at 400 nm excitation have respectively theluminescence peak wavelengths at a green region in case of CaSi₂O₂N₂:Euof Example 1, at a yellow to red region in case of Ca₂Si₅N₈:Eu, and at ablue region in case of (Ca_(0.93), Eu_(0.05), Mn_(0.02))₁₀(PO₄)₆Cl₂. Itexhibits a luminescence color at a white region by the color mixture oflights from these phosphors. It emits white light with various colortastes by changing the compounding amounts of these phosphors.Accordingly, when a light-emitting device having a fixed white lightusing ultraviolet light as an excitation light source is produced, theluminescence color can be changed by only changing the kind ofphosphors, compounding ratio and the like.

Example 29 Light-Emitting Device

The light-emitting device of Example 29 is a white light-emitting deviceusing a light-emitting element having the luminescence peak wavelengthat 460 nm, as an excitation light source. The light-emitting device ofExample 29 has also a structure shown in FIG. 1.

Namely, in the light-emitting device of Example 29, the semiconductorlayer 2 of an n-type GaN layer and p-type GaN layer is formed on thesapphire substrate 1, the electrode 3 is provided at said n-type andp-type semiconductor layers 2, said electrode 3 is electricallyconnected with the lead frame 13 by the electroconductive wire 14. Theupper portion of the light-emitting device 10 is covered with thephosphor 11 and the coating member 12, and the outer peripheral portionsof the lead frame 13, the phosphor 11 and the coating member 12 arecovered with the mold member 15. The semiconductor layer 2 is obtainedby laminating n⁺GaN:Si, n-AlGaN:Si, n-GaN, GaInN QWs, p-GaN:Mg,p-AlGaN:Mg, and p-GaN:Mg in order on the sapphire substrate 1. Theportion of said n⁺GaN:Si is etched and an n-type electrode is formed. Ap-type electrode is formed on said p-GaN:Mg layer. Copper with Fe isused for the lead frame 13. A cup for mounting the light-emitting device10 is provided on the upper portion of the mount lead 13 a, and thelight-emitting element 10 is die-bonded at about the central part bottomof said cup. Gold is used for the electroconductive wire 14, and Niplating is carried out on the bump 4 for electrically connecting theelectrode 3 with the electroconductive wire 14. As the coating member12, a mixture which mixed an epoxy resin and a dispersant, bariumtitanate, titanium oxide and the fore-mentioned phosphor 11 at a fixedproportion is used. The epoxy resin is used for the mold member 15. Thecannonball type light-emitting device 1 is a column in which the moldmember 15 is a radius of 2 to 4 mm, height is about 7 to 10 mm, and theupper part is a hemisphere.

When current is run in the light-emitting device of Example 29, the bluelight-emitting element 10 having the luminescence spectrum with a peakwave length of about 460 nm emits light. The phosphor 11 which coversthe semiconductor layer 2 carries out the conversion of color tone. As aresult, there can be provided the light-emitting device of Example 29which emits white light.

The phosphor 11 of the light-emitting device of Example 29 related tothe present invention uses the phosphor 11 which mixed the oxynitridephosphor of Example 1 and the nitride phosphor represented byCaSrSi₅N₈:Eu. Said phosphor 11 is mixed with the coating member 12.

The portion of light from the light-emitting element 10 transmits thelight-emitting device of Example 29. Further, the portion of light fromthe light-emitting element 10 excites the phosphor 11, the phosphor 11carries out the wavelength conversion, and red light is emitted from thegreen color of the oxynitride phosphor and the yellow red color of thenitride phosphor. There can be provided the light-emitting device whichemits white light, by the color mixture of blue light from theselight-emitting elements 10, green light from the oxynitride phosphor,and yellow red to red light from the nitride phosphor.

Example 30 Light-Emitting Device

FIG. 30 is a chart showing the cap type light-emitting device of Example30 related to the present invention.

In FIG. 30 showing the light-emitting device of Example 30, the samecodes are imparted for the same members as those in the light-emittingdevice of Example 28, and illustrations thereof are abbreviated. As thelight-emitting element 10, a light-emitting element having theluminescence peak wavelength at 400 nm is used.

The light-emitting device of Example 30 is constituted by covering thecap 16 comprising a transparent resin in which phosphors (notillustrated) were dispersed on the surface of the mold member of thelight-emitting device of Example 28.

A cup for mounting the light-emitting device 10 is provided on the upperportion of the mount lead 13 a, and said light-emitting element 10 isdie-bonded at about the central part bottom of said cup. The phosphor 11is provided on the upper part of said cap so as to cover thelight-emitting element 10 in the light-emitting device of Example 30,but the phosphor may be contained only in the cap 16 in thelight-emitting device of Example 30. When the phosphor 11 is notprovided on the light-emitting element 10, the phosphor is able not todirectly receive the influence of heat generated from the light-emittingelement 10.

Further, the phosphor is homogeneously dispersed in a transparent resinin case of the cap 16. The transparent resin containing the phosphor ismolded in a shape which is fitted for the shape of the mold member 15.Alternatively, there is also possible a process of charging thetransparent resin containing the phosphor into a fixed mold, thenpushing the light-emitting device 1 into said mold and molding it. Asthe specific example of the transparent resin of the cap 16, there areused transparent resins excellent in temperature properties and weatherresistance such as an epoxy resin, a urea resin and a silicone resin;silica sol, glass, an inorganic binder and the like. In addition to theresins mentioned above, there can be also used thermosetting resins suchas a melamine resin and a phenol resin. Further, there can be also usedthermoplastic resins such as a polyethylene, a polypropylene, apoly(vinyl chloride) and a polystyrene; thermoplastic rubbers such as astyrene-butadiene block copolymer and a segmented polyurethane, etc.Further, a dispersant, barium titanate, titanium oxide, aluminum oxideand the like may be contained together with the phosphor. Further, alight stabilizer and a coloring agent may be contained. The nitridephosphor of Ca₂Si₅N₈:Eu and the phosphor of (Ca_(0.95),Eu_(0.05))₁₀(PO₄)₆Cl₂ are used for the phosphors contained in the cap16. The nitride phosphor of Example 3 is used for the phosphor 11 usedin the cap of the mount lead 13 a. However, since the phosphors are usedin the cap 16, there may be a structure in which the cap 16 contains theoxynitride phosphor and only the coating member 12 exists in the cap ofthe mount lead 13 a.

In the light-emitting device thus constituted, the portion of lightemitted from the light-emitting element 10 excites the oxynitridephosphor of the phosphor 11 and green light is emitted from theoxynitride phosphor. Further, the portion of light emitted from thelight-emitting element 10 or the portion of light emitted from theoxynitride phosphor excites the phosphor of the cap 16, and red light isemitted from blue and yellow. The green light of the oxynitride phosphoris mixed with the red light from the blue color and yellow color of thephosphor of the cap 16, and as a result, white light is released fromthe surface of the cap 16.

Examples 31 to 79 below are Examples related to the oxynitride phosphorrelated to the present invention, respectively.

Examples 31 to 56

Table 6 shows the properties of Examples 31 to 56 of the oxynitridephosphor related to the present invention.

Further, FIG. 32 is a chart showing the change of the luminescenceefficiency caused by the change of the content of the activator Rcontained in the composition of the oxynitride phosphor. The excitationlight source is light nearby 400 nm. FIG. 33 is a chart showing thechange of the luminescence efficiency caused by the change of thecontent of the activator R contained in the composition of theoxynitride phosphor. The excitation light source is light nearby 460 nm.FIG. 34 is a CIE chromaticity chart showing the change of the color tonecaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor. FIG. 35 is an expanded CIEchromaticity chart of FIG. 34. FIG. 36 is a chart showing theluminescence spectrum when the oxynitride phosphor was excited at Ex=400nm. FIG. 37 is a chart showing the luminescence spectrum when theoxynitride phosphor was excited at Ex=460 nm. FIG. 38 is a chart showingthe normalized excitation spectrum of the oxynitride phosphor. FIG. 39is a chart showing the reflection spectrum of the oxynitride phosphor.FIG. 40A is an SEM photo photographed the oxynitride phosphor of Example36 at a magnification of 1000-fold, FIG. 40B is an SEM (scanningelectron microscope) photo photographed the oxynitride phosphor ofExample 36 at a magnification of 5000-fold, and FIG. 40C is an SEM photophotographed the oxynitride phosphor of Example 36 at a magnification of10000-fold.

TABLE 6 Luminescence Energy Quantum Compounding Color Color brightness Yefficiency efficiency ratio x of Eu tone x tone y (%) E (%) Q (%) Ex =400 nm Example 31 0.01 0.333 0.614 81.0 81.7 81.0 Example 32 0.015 0.3400.612 87.2 87.8 87.3 Example 33 0.02 0.341 0.612 95.1 95.5 94.9 Example34 0.025 0.345 0.609 97.3 97.5 96.9 Example 35 0.03 0.349 0.608 97.798.1 97.9 Example 36 0.035 0.356 0.604 100.0 100.0 100.0 Example 37 0.040.356 0.604 97.9 98.4 98.5 Example 38 0.045 0.363 0.600 97.4 97.7 97.9Example 39 0.05 0.367 0.598 95.4 95.8 96.2 Example 40 0.07 0.378 0.59089.0 90.1 91.2 Example 41 0.08 0.387 0.584 89.6 91.1 92.4 Example 42 0.10.394 0.579 87.3 89.5 91.4 Example 43 0.12 0.405 0.571 85.5 88.1 90.4Example 44 0.14 0.416 0.562 84.8 88.8 91.5 Example 45 0.18 0.422 0.55884.8 89.5 92.4 Example 46 0.18 0.425 0.556 79.9 84.3 87.0 Example 47 0.20.430 0.552 72.5 76.5 79.5 Example 48 0.22 0.438 0.546 71.7 76.3 79.5Example 49 0.24 0.442 0.543 68.8 73.7 77.0 Example 50 0.26 0.446 0.53961.1 66.2 69.2 Example 51 0.28 0.450 0.536 57.7 62.9 66.1 Example 52 0.30.449 0.537 48.3 52.9 55.4 Example 53 0.4 0.462 0.526 38.6 43.4 45.9Example 54 0.5 0.471 0.519 31.0 35.7 38.0 Example 55 0.6 0.476 0.51423.0 26.9 28.7 Example 56 0.7 0.482 0.508 16.6 20.2 21.8 Ex = 460 nmExample 31 0.01 0.334 0.623 59.6 57.4 55.0 Example 32 0.015 0.339 0.62067.0 64.6 62.2 Example 33 0.02 0.340 0.621 81.5 78.0 75.0 Example 340.025 0.343 0.618 83.2 79.8 77.0 Example 35 0.03 0.347 0.616 84.3 81.078.1 Example 36 0.035 0.352 0.614 94.1 89.8 86.7 Example 37 0.04 0.3540.612 91.2 87.4 84.5 Example 38 0.045 0.358 0.610 96.3 92.2 89.2 Example39 0.05 0.363 0.607 96.6 92.7 89.9 Example 40 0.07 0.375 0.597 97.1 94.092.0 Example 41 0.08 0.380 0.593 97.7 95.0 93.0 Example 42 0.1 0.3900.586 97.4 95.4 94.2 Example 43 0.12 0.400 0.578 100.0 98.5 97.9 Example44 0.14 0.408 0.571 99.6 99.1 98.7 Example 45 0.18 0.414 0.566 99.4100.0 100.0 Example 46 0.18 0.417 0.564 95.2 95.9 96.0 Example 47 0.20.424 0.559 89.3 90.2 90.8 Example 48 0.22 0.430 0.555 91.5 93.4 94.2Example 49 0.24 0.434 0.551 87.0 89.1 90.1 Example 50 0.26 0.438 0.54778.2 81.0 82.1 Example 51 0.28 0.441 0.545 73.9 77.0 78.3 Example 52 0.30.441 0.545 61.4 63.6 64.6 Example 53 0.4 0.453 0.535 53.3 56.3 57.7Example 54 0.5 0.460 0.529 43.7 46.9 48.4 Example 55 0.6 0.466 0.52433.6 36.6 37.8 Example 56 0.7 0.471 0.518 23.4 26.5 27.6

Examples 31 to 56 are SrSi₂O₂N₂:Eu. When Examples 31 to 56 wereirradiated using the excitation light source around 400 nm, theluminescence brightness, energy efficiency and quantum efficiency ofother Examples are shown with their relative values based on the basisof Example 36 in which the luminescence brightness, energy efficiencyand quantum efficiency were highest. When Examples 31 to 56 wereirradiated using the excitation light source around 460 nm, theluminescence brightness of other Examples are shown with their relativevalues based on the basis of Example 43 in which the luminescencebrightness, energy efficiency and quantum efficiency were highest.Further, the energy efficiency and quantum efficiency of other Examplesare shown with their relative values based on the basis of Example 45 inwhich the energy efficiency and quantum efficiency were highest.

Firstly, Sr₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were used as the raw materials.Said raw materials were crushed at 0.1 to 3.0 μm respectively. After thecrushing, Examples 31 to 56 were weighed so as to be the fixed amounts.Since the portion of Sr is substituted with Eu, the oxynitride phosphoris represented by the general formula Sr_((1−X))Eu_(X)Si₂O₂N₂:Eu(0<X<1).

After weighing the above-mentioned amounts, fixed amounts of Sr₃N₂,Si₃N₄, SiO₂ and Eu₂O₃ were mixed under nitrogen atmosphere in a glovebox until uniformity.

In Example 35, Sr₃N₂:Si₃N₄:SiO₂:Eu₂O₃ of the mix ratio (molar ratio) ofthe raw materials is Sr:Si:O:Eu=0.97:2:2:0.03. Sr₃N₂, Si₃N₄, SiO₂ andEu₂O₃ were weighed so as to be the mixing ratio, and mixed. Examples 31to 56 changed the Sr concentration of Sr_((1−X))Eu_(X)Si₂O₂N₂ and thecompounding ratio of Eu so as to be a fixed molar ratio. The compoundingratio of Eu in Table shows the molar ratio of Eu.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1500° C. for about 5 hours.

The objective oxynitride phosphors were obtained thereby. Thetheoretical composition of the oxynitride phosphors obtained isSr_((1−X))Eu_(X)Si₂O₂N₂ (0<X<1).

When the % by weight of O and N in the oxynitride phosphor of Example 35was measured, O and N were contained by 15.3% by weight and 10.1% byweight respectively. The weight ratio of O to N is O:N=1:0.66.

The calcination of the oxynitride phosphors related to Examples 31 to 56is carried out in ammonia atmosphere using a boron nitride crucible. Acrucible made of a metal is not preferably used for the crucible. Forexample, when the crucible made of a metal is used, it is consideredthat the crucible is eroded and it causes the lowering of luminescenceproperties. Accordingly, it is preferable to use a crucible made ofceramics such as alumina.

Any of the calcined products of Examples 31 to 56 is crystalline powderor granules. The particle diameter was nearly 1 to 5 μm.

The excitation spectra of the oxynitride phosphors of Examples 31 to 56were measured. As a result of the measurement, they are strongly excitedat 290 nm to 490 nm.

The oxynitride phosphors of Examples 31 to 56 were excited by Ex=400 nm.The oxynitride phosphor of Example 31 has a luminescence color at ayellow green region of the color tone, x=0.333 and the color toney=0.614. The oxynitride phosphor of Example 36 has a luminescence colorat a yellow green region of the color tone, x=0.356 and the color toney=0.604. When the compounding ratio of Eu is increased, the color tone xis shifted to a right direction and the color tone y is shifted to adown direction in the chromaticity coordinate. When the compoundingratio of Eu is increased, the luminescence brightness is graduallyenhanced, and the luminescence brightness was highest in case of Example36. When the compounding ratio of Eu is increased, the luminescencebrightness is lowered. On the other hand, when the compounding ratio ofEu is increased, the quantum efficiency is gradually enhanced, and thequantum efficiency was highest in case of Example 36. When thecompounding ratio of Eu is further increased, the quantum efficiency islowered. Here at, Examples 31 to 47 can provide the oxynitride phosphorhaving a desired color tone while keeping the high luminescencebrightness and high quantum efficiency.

The oxynitride phosphors of Examples 31 to 56 were excited by Ex=460 nm.Since Ex=460 nm is a wavelength region which is often used in a bluelight-emitting element, excitation was carried out at said wavelengthregion. As a result, the oxynitride phosphor of Example 31 has aluminescence color at a yellow green region of the color tone, x=0.334and the color tone y=0.623. When the compounding ratio of Eu isincreased, the color tone x is shifted to a right direction and thecolor tone y is shifted to a down direction in the chromaticitycoordinate. The oxynitride phosphor of Example 43 has a luminescencecolor at a yellow green region of the color tone, x=0.400 and the colortone y=0.578. Further, when the compounding ratio of Eu is increased,the luminescence brightness is gradually enhanced, and the luminescencebrightness was highest in case of Example 43. When the compounding ratioof Eu is further increased, the luminescence brightness is lowered. Onthe other hand, when the compounding ratio of Eu is increased, thequantum efficiency is gradually enhanced, and the quantum efficiency washighest in case of Example 45. When the compounding ratio of Eu isfurther increased, the quantum efficiency is lowered. Here at, Examples32 to 51 can provide the oxynitride phosphor having a desired color tonewhile keeping the high luminescence brightness and high quantumefficiency.

Further, the temperature properties of the oxynitride phosphors ofExamples 31 to 56 were extremely good. The temperature properties areshown by relative brightness in which the luminescence brightness at 25°C. is 100%. The particle diameter is a value according to an airtransmission process called F.S.S. No. (Fisher Sub Sieve Sizer's No.).The temperature properties of Examples 31 to 56 are 85% or more at 100°C. They were 55% or more at 200° C.

When the X-ray diffraction images of the above-mentioned theseoxynitride phosphors were measured, any image shows a sharp diffractionpeak, and it was cleared that the phosphors obtained were crystallinecompounds having regularity. The crystal structure was the rhombicsystem.

Examples 57 to 70

Table 7 shows the properties of Examples 57 to 70 of the oxynitridephosphors related to the present invention.

Further, FIG. 41 is a chart showing the change of the luminescenceefficiency caused by the change of the content of the activator Rcontained in the composition of the oxynitride phosphor. The excitationlight source is light nearby 400 nm. FIG. 42 is a chart showing thechange of the luminescence efficiency caused by the change of thecontent of the activator R contained in the composition of theoxynitride phosphor. The excitation light source is light nearby 460 nm.FIG. 43 is a CIE chromaticity chart showing the change of the color tonecaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphor. FIG. 44 is an expanded CIEchromaticity chart of FIG. 43. FIG. 45 is a chart showing theluminescence spectrum when the oxynitride phosphor was excited at Ex=400nm. FIG. 46 is a chart showing the luminescence spectrum when theoxynitride phosphor was excited at Ex=460 nm. FIG. 47 is a chart showingthe normalized excitation spectrum of the oxynitride phosphor. FIG. 48is a chart showing the reflection spectrum of the oxynitride phosphor.

TABLE 7 Ex = 400 nm Compounding Luminescence ratio x of Eu peak (nm)Color tone x Color tone y Example 57 0.01 558 0.442 0.549 Example 580.02 559 0.428 0.546 Example 59 0.03 559 0.433 0.543 Example 60 0.06 5650.444 0.536 Example 61 0.09 566 0.451 0.530 Example 62 0.12 564 0.4560.526 Example 63 0.15 566 0.460 0.524 Example 64 0.2 567 0.464 0.522Example 65 0.3 567 0.473 0.516 Example 66 0.4 570 0.485 0.506 Example 670.5 580 0.499 0.494 Example 68 0.6 572 0.502 0.492 Example 69 0.7 5740.500 0.494 Example 70 0.8 572 0.497 0.496 Luminescence Energy QuantumCompounding Peak intensity brightness Y efficiency efficiency ratio x ofEu ( ) (%) E (%) Q (%) Example 57 0.01 99.3 99.4 98.7 98.5 Example 580.02 100.0 100.0 100.0 100.0 Example 59 0.03 94.3 94.1 94.6 95.0 Example60 0.06 76.8 76.5 78.7 79.6 Example 61 0.09 70.0 69.5 72.7 74.1 Example62 0.12 73.1 72.7 77.2 78.8 Example 63 0.15 74.0 72.9 77.2 79.0 Example64 0.2 79.2 77.1 81.7 83.7 Example 65 0.3 80.2 76.6 82.0 84.3 Example 660.4 71.3 67.8 76.0 79.0 Example 67 0.5 69.4 65.4 76.2 79.9 Example 680.6 48.7 45.1 51.7 53.9 Example 69 0.7 49.4 45.8 51.9 54.1 Example 700.8 28.7 26.9 30.2 31.4

Examples 57 to 70 are the oxynitride phosphors represented byCaSi₂O₂N₂:Eu. When Examples 57 to 70 were irradiated using theexcitation light source around 400 nm, the luminescence brightness,energy efficiency and quantum efficiency of other Examples are shownwith their relative values based on the basis of Example 58 in which theluminescence brightness, energy efficiency and quantum efficiency werehighest. When Examples 57 to 70 were irradiated using the excitationlight source around 460 nm, the luminescence brightness of otherExamples are shown with their relative values based on the basis ofExample 65 in which the luminescence brightness, energy efficiency andquantum efficiency were highest.

Ca₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were used as the raw materials. Theproduction of the oxynitride phosphors of Examples 57 to 70 was carriedout using these raw materials and the similar production process asExample 31. The production was carried out so that said raw materialsare a fixed molar ratio. The theoretical composition of the oxynitridephosphors obtained is Ca_((1−X))Eu_(X)Si₂O₂N₂ (0<X<1). The portion of Cais substituted with Eu. The compounding molar ratio of Eu in Table showsthe molar ratio of Eu.

When the % by weight of O and N in the oxynitride phosphor of Example 58was measured, O and N were contained by 19.5% by weight and 17.5% byweight respectively. The weight ratio of O to N is O:N=1:0.90.

Any of the calcined products of Examples 57 to 70 is crystalline powderor granules. The particle diameter was nearly 1 to 8 μm.

The excitation spectra of the oxynitride phosphors of Examples 57 to 70were measured. As a result of the measurement, they are strongly excitedat 290 nm to 520 nm.

The oxynitride phosphors of Examples 57 to 70 were excited by Ex=400 nm.The oxynitride phosphor of Example 58 has a luminescence color at ayellow green region of the color tone, x=0.428 and the color toney=0.546. The oxynitride phosphor of Example 57 has a luminescence colorat a yellow green region of the color tone, x=0.422 and the color toney=0.549. When the compounding ratio of Eu is increased, the color tone xis shifted to a right direction and the color tone y is shifted to adown direction in the chromaticity coordinate. The high luminescencebrightness, energy efficiency and high quantum efficiency were highestin case of Example 58. Here at, Examples 56 to 67 can provide theoxynitride phosphor having a desired color tone while keeping the highluminescence brightness and high quantum efficiency.

The oxynitride phosphors of Examples 57 to 70 were excited by Ex=460 nm.Since Ex=460 nm is a wavelength region which is often used in a bluelight-emitting element, excitation was carried out at said wavelengthregion. As a result, the oxynitride phosphor of Example 65 has aluminescence color at a yellow green region of the color tone, x=0.464and the color tone y=0.524. When the compounding ratio of Eu isincreased, the color tone x is shifted to a right direction and thecolor tone y is shifted to a down direction in the chromaticitycoordinate.

Further, when the compounding ratio of Eu is increased, the luminescencebrightness, energy efficiency and quantum efficiency are graduallyenhanced, and the luminescence brightness was highest in case of Example65. Further, when the compounding ratio of Eu is further increased, theluminescence brightness is lowered. Here at, Examples 57 to 69 canprovide the oxynitride phosphor having a desired color tone whilekeeping the high luminescence brightness and high quantum efficiency.

When the X-ray diffraction images of the above-mentioned theseoxynitride phosphors were measured, any image shows a sharp diffractionpeak, and it was cleared that the phosphors obtained were crystallinecompounds having regularity. The crystal structure was the rhombicsystem.

Examples 71 to 78

Table 8 shows the properties of Examples 71 to 78 of the oxynitridephosphors related to the present invention.

Further, FIG. 49 is a chart showing the change of the peak intensitycaused by the change of the content of the activator R contained in thecomposition of the oxynitride phosphors. The excitation light sourcesare lights nearby 400 nm and 460 nm. FIG. 50 is a chart showing thechange of the luminescence efficiency caused by the change of thecontent of the activator R contained in the composition of theoxynitride phosphors. The excitation light source is light nearby 400nm. FIG. 51 is a chart showing the luminescence spectra when theoxynitride phosphors were excited at Ex=400 nm. FIG. 52 is a chartshowing the luminescence spectra when the oxynitride phosphors wereexcited at Ex=460 nm. FIG. 53 is a chart showing the normalizedexcitation spectra of the oxynitride phosphors. FIG. 54 are a chartshowing the reflection spectra of the oxynitride phosphors.

TABLE 8 Ex = 400 nm Peak Compounding Luminescence intensity ratio x ofEu peak (nm) Color tone x Color tone y ( ) Example 71 0.01 495 0.0900.458 100.3 Example 72 0.02 496 0.101 0.485 100.0 Example 73 0.03 4970.116 0.507 90.1 Example 74 0.04 498 0.113 0.504 89.2 Example 75 0.05499 0.132 0.521 83.6 Example 76 0.1 498 0.247 0.477 22.5 Example 77 0.15518 0.289 0.556 8.4 Example 78 0.2 531 0.317 0.599 5.7 LuminescenceEnergy Compounding brightness Y efficiency E Quantum ratio x of Eu (%)(%) efficiency Q (%) Example 71 0.01 90.8 96.6 96.0 Example 72 0.02100.0 100.0 100.0 Example 73 0.03 102.3 96.0 96.5 Example 74 0.04 95.792.1 92.6 Example 75 0.05 102.9 92.9 94.1 Example 76 0.1 54.4 42.3 45.0Example 77 0.15 40.3 23.7 25.5 Example 78 0.2 27.7 14.2 15.3 Ex = 460 nmPeak Compounding Luminescence intensity ratio x of Eu peak (nm) ( )Example 71 0.01 495 95.2 Example 72 0.02 496 100.0 Example 73 0.03 49894.2 Example 74 0.04 498 96.7 Example 75 0.05 499 93.3 Example 76 0.1500 28.2 Example 77 0.15 504 9.1 Example 78 0.2 536 4.0

Examples 71 to 78 are BaSi₂O₂N₂:Eu. When Examples 71 to 78 wereirradiated using the excitation light source around 400 nm, theluminescence brightness, energy efficiency and quantum efficiency ofother Examples are shown with their relative values based on the basisof Example 72 in which the luminescence brightness, energy efficiencyand quantum efficiency were highest. When Examples 71 to 78 wereirradiated using the excitation light source around 460 nm, the peakintensity of other Examples is shown with their relative values based onthe basis of Example 72.

Ba₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were used as the raw materials. Theproduction of the oxynitride phosphors of Examples 71 to 78 was carriedout using these raw materials and the similar production process asExample 31. The production was carried out so that said raw materialsare a fixed molar ratio. The theoretical composition of the oxynitridephosphors obtained is Ba_((1−X))Eu_(X)Si₂O₂N₂ (0<X<1). The portion of Bais substituted with Eu. The compounding molar ratio of Eu in Table showsthe molar ratio of Eu.

When the % by weight of O and N in the oxynitride phosphor of Example 72was measured, O and N were contained by 11.3% by weight and 10.6% byweight respectively. The weight ratio of O to N is O:N=1:0.94.

Any of the calcined products of Examples 71 to 78 is crystalline powderor granules. The particle diameter was nearly 1 to 8 μm.

The excitation spectra of the oxynitride phosphors of Examples 71 to 78were measured. As a result of the measurement, they are strongly excitedat 290 nm to 480 nm.

The oxynitride phosphors of Examples 71 to 78 were excited by Ex=400 nm.The oxynitride phosphor of Example 72 has a luminescence color at agreen region of the color tone, x=0.101 and the color tone y=0.485. Theoxynitride phosphor of Example 75 has a luminescence color at a greenregion of the color tone, x=0.132 and the color tone y=0.521. When thecompounding ratio of Eu is increased, the color tone x is shifted to aright direction and the color tone y is shifted to an up direction inthe chromaticity coordinate. The high luminescence brightness washighest in case of Example 75, and the energy efficiency and quantumefficiency were highest in case of Example 72. Here at, Examples 71 to75 can provide the oxynitride phosphor having a desired color tone whilekeeping the high luminescence brightness and high quantum efficiency.

The oxynitride phosphors of Examples 71 to 78 were excited by Ex=460 nm.Since Ex=460 nm is a wavelength region which is often used in a bluelight-emitting element, excitation was carried out at said wavelengthregion. As a result, the oxynitride phosphor of Example 72 has thehighest peak intensity.

Further, the temperature properties of Examples 71 to 78 were excellent.The temperature properties of Examples 71 to 78 were 90% or more at 100°C. They were 65% or more at 200° C.

When the X-ray diffraction images of these oxynitride phosphors weremeasured, any image shows a sharp diffraction peak, and it was clearedthat the phosphors obtained were crystalline compounds havingregularity. The crystal structure was the rhombic system.

Example 79

FIG. 55 is a chart showing the luminescence spectrum when the oxynitridephosphor of Example 79 was excited at Ex=400 nm. FIG. 56 is a chartshowing the luminescence spectrum when the oxynitride phosphor ofExample 79 was excited at Ex=460 nm. FIG. 57 is a chart showing theexcitation spectrum of the oxynitride phosphor of Example 79. FIG. 58 isa chart showing the reflection spectrum of the oxynitride phosphor ofExample 79. FIG. 59A is an SEM photo photographed the oxynitridephosphor of Example 79 at a magnification of 1000-fold. FIG. 59B is anSEM photo photographed the oxynitride phosphor of Example 79 at amagnification of 10000-fold.

Example 79 is CaSi₂O₂N₂:Eu.

Firstly, Ca₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were used as the raw materials.Said raw materials were respectively crushed at 0.1 to 3.0 μm. After thecrushing, Example 79 used the under-mentioned amounts of raw materials.

-   Ca₃N₂:6.01 g-   Si₃N₄:5.99 g-   SiO₂:7.36 g-   Eu₂O₃:0.66 g

After weighing the above-mentioned amounts, production was carried outby the similar production process as Examples 31 to 56. The compoundingratio of Eu of Example 79 is 0.43% by mol.

In Example 79, the mix ratio (molar ratio) of the raw materials isCa₃N₂:Si₃N₄:SiO₂:Eu₂O₃=1:1.05:3.02:0.046.

The objective oxynitride phosphor was obtained thereby. The theoreticalcomposition of the oxynitride phosphor obtained is CaSi₂O₂N₂:Eu.

When the % by weight of O and N in the oxynitride phosphor of Example 79was measured, O and N were contained by 18.8% by weight and 17.1% byweight respectively. The weight ratio of O to N is O:N=1:0.94.

The oxynitride phosphors of Example 79 was excited by Ex=400 nm. Theoxynitride phosphor of Example 79 has a luminescence color at a yellowgreen region of the color tone, x=0.434 and the color tone y=0.543.Further, the temperature properties of Example 79 were excellent.

When the X-ray diffraction images of these oxynitride phosphors weremeasured, any image shows a sharp diffraction peak, and it was clearedthat the phosphors obtained were crystalline compounds havingregularity. The crystal structure was the rhombic system.

Example 80 Light-Emitting Device

The light-emitting device of Example 80 was produced using theabove-mentioned oxynitride phosphor. As the excitation light source, thelight-emitting element having the luminescence spectrum of 400 nm. Asthe phosphor, CaSi₂O₂N₂:Eu of Example 79, Ca₂Si₅N₈:Eu and (Ca_(0.93),Eu_(0.05), Mn_(0.02))₁₀(PO₄)₆Cl₂ are used. The light-emitting device ofExample 80 is a structure shown in FIG. 1. FIG. 26 is a plane viewshowing the light-emitting element related to the present invention.FIG. 27 is a section view showing the A-A′ of the light-emitting elementrelated to the present invention. FIG. 61 is a chromaticity chart (JISZ8110) showing the chromaticity coordinate of the light-emitting device1 related to the present invention.

In the light-emitting device of Example 80, the similar light-emittingelement as that used in the light-emitting device of Example 28 wasused.

The properties of the light-emitting device 1 of Example 80 are shown inTable 9.

TABLE 9 Luminous Radiation intensity Peak analysis measurementwavelength Current Voltage Radiometric Photometric Peak If (mA) Vf (V)(mW) (lm) (nm) Light 20 3.4 6.2 1.84 464 emitting device Color Averagecolor Lump Color Color temperature rendering efficiency tone x tone yTcp(K) Ra (lm/W) Light 0.356 0.368 4690 82.2 27.1 emitting device

The light-emitting device of Example 80 constituted as above exhibits aluminescence color at a white region. The light-emitting device ofExample 80 exhibits a luminescence spectrum having the luminescence peakwavelengths at 360 to 430 nm, 430 to 500 nm and 500 to 730 nm. Morespecifically, it exhibits a luminescence spectrum having theluminescence peak wavelengths at 390 to 410 nm, 455 to 475 nm and 550 to600 nm. The phosphors excited by the light-emitting element at 400 nmexcitation have respectively the luminescence peak wavelengths at agreen region in case of CaSi₂O₂N₂:Eu of Example 79, at a yellow to redregion in case of Ca₂Si₅N₈:Eu, and at a blue region in case of(Ca_(0.93), Eu_(0.05), Mn_(0.02))₁₀(PO₄)₆Cl₂. It exhibits a luminescencecolor at a white region by the color mixture of lights from thesephosphors. It emits white light with various color tastes by changingthe compounding amounts of these phosphors. Accordingly, when thelight-emitting device having a fixed white light using ultraviolet lightas an excitation light source is produced, the luminescence color can bechanged by only changing the kind of phosphors, compounding ratio andthe like.

Example 81 Light-Emitting Device

The light-emitting device of Example 81 relates to a white colorlight-emitting device using a light-emitting element having theluminescence peak wavelength at 460 nm, as an excitation light source,and is constituted in like manner as Example 29, except for using thephosphor 11 which mixes the oxynitride phosphor of Example 31 and thenitride phosphor represented by CaSrSi₅N₈:Eu, in the light-emittingdevice of Example 29 (the structure of FIG. 1).

When current is run in the light-emitting device of Example 81, the bluelight-emitting element 10 having the luminescence spectrum with a peakwave length at about 460 nm emits light. The phosphor 11 which coversthe semiconductor layer 2 carries out the conversion of color tone. As aresult, there can be provided the light-emitting device of Example 81which emits white light.

Namely, the portion of light from the light-emitting element 10transmits the light-emitting device of Example 81. Further, the portionof light from the light-emitting element 10 excites the phosphor 11, thephosphor 11 carries out the wavelength conversion, and red light isemitted from the green color of the oxynitride phosphor and the yellowred color of the nitride phosphor. There can be provided thelight-emitting device which emits white light, by the color mixture ofblue light from these light-emitting elements 10, green light from theoxynitride phosphor, and yellow red to red light from the nitridephosphor.

Example 82 Light-Emitting Device

The light-emitting device of Example 82 is constituted in like manner asthe light-emitting device of Example 30 except for changing thephosphors below in the light-emitting device of Example 30.

Namely, in the light-emitting device of Example 82, the nitride phosphorof Ca₂Si₅N₈:Eu and the phosphor of (Ca_(0.95), Eu_(0.05))₁₀(PO₄)₆Cl₂ areintroduced in the cap 16, and the oxynitride phosphor of Example 33 isused as the phosphor 11 in the cup of the mount lead 13 a. Further, itis similar as Example 30 that all of the phosphors may be contained inthe cap 16.

In the light-emitting device of Example 82 thus constituted, the portionof light released from the light-emitting element 10 excites theoxynitride phosphor of the phosphor 11 to emit green light. Further, theportion of light emitted from the light-emitting element 10 or theportion of light emitted from the oxynitride phosphor excites thephosphor of the cap 16, and red light is emitted from blue and yellow.The green light of the oxynitride phosphor is mixed with the red lightfrom the blue color and yellow color of the phosphor of the cap 16, andas a result, white light is released from the surface of the cap 16.

Examples 83 to 87 below are Examples related to Embodiment 6 related tothe present invention.

Examples 83 to 87

FIG. 63 is a chart showing the luminescence spectra when the oxynitridephosphors of Examples 83 to 87 were excited at Ex=400 nm. FIG. 64 is achart showing the luminescence spectra when the oxynitride phosphors ofExamples 83 to 87 were excited at Ex=460 nm. FIG. 65 is a chart showingthe excitation spectra of the oxynitride phosphors of Examples 83 to 87.FIG. 66 is a chart showing the reflection spectra of the oxynitridephosphors of Examples 83 to 87. FIG. 67 is an SEM photo photographingthe oxynitride phosphor of Example 83. FIG. 67( a) is an SEM photophotographed at a magnification of 1000-fold, and FIG. 67( b) is an SEMphoto photographed at a magnification of 5000-fold.

In Examples 83 to 87, the portion of Ba is substituted with Eu, and saidEu concentration is changed. Example 83 is Ba_(0.97)Eu_(0.03)Si₂O₂N₂.Example 84 is Ba_(0.95)Eu_(0.05)Si₂O₂N₂. Example 85 isBa_(0.90)Eu_(0.10)Si₂O₂N₂. Example 86 is Ba_(0.85)Eu_(0.15)Si₂O₂N₂.Example 87 is Ba_(0.80)Eu_(0.20)Si₂O₂N₂.

Firstly, Ba₃N₂, Si₃N₄, SiO₂ and Eu₂O₃ were used as the raw materials.Said raw materials were crushed at 0.1 to 3.0 μm. Example 83 used theunder-mentioned amounts of the raw materials so as to be theabove-mentioned composition after crushing. Wherein a molar ratio of Euto Ba is Ba:Eu=0.97:0.03.

-   Ba₃N₂:5.60 g-   Si₃N₄:1.88 g-   SiO₂:2.31 g-   Eu₂O₃:0.21 g

After weighing the above-mentioned amounts, Ba₃N₂, Si₃N₄, SiO₂ and Eu₂O₃were mixed until uniformity.

The above-mentioned compounds were mixed, the mixture was charged in aboron nitride crucible in ammonia atmosphere, and calcination wascarried out at about 1500° C. for about 5 hours.

The objective oxynitride phosphor was obtained thereby. The theoreticalcomposition of the oxynitride phosphor obtained is BaSi₂O₂N₂:Eu.

When the % by weight of O and N in the oxynitride phosphor of Example 83was measured, O and N were contained by 12.1% by weight and 8.9% byweight respectively. The weight ratio of O to N is O:N=1:0.74.

The calcination of the oxynitride phosphor related to Examples iscarried out in ammonia atmosphere using a boron nitride crucible. Acrucible made of a metal is not preferably used for the crucible. Whenthe crucible made of a metal is used, it is considered that the crucibleis eroded and it causes the lowering of luminescence properties.Accordingly, it is preferable to use a crucible made of ceramics such asalumina.

Example 84 changes the compounding ratio of Eu. Example 84 is theoxynitride phosphor in which the portion of Ba was substituted with Eu.The under-mentioned amounts of crushed powders were weighed. Wherein amolar ratio of Eu to Ba is Ba:Eu=0.95:0.05.

-   Ba₃N₂:5.48 g-   Si₃N₄:1.91 g-   SiO₂:2.28 g-   Eu₂O₃:0.35 g

Said raw materials were mixed and calcination was carried out under thesame conditions as Example 83.

Example 85 changes the compounding ratio of Eu. Example 85 is theoxynitride phosphor in which the portion of Ba was substituted with Eu.The under-mentioned amounts of crushed powders were weighed. Wherein amolar ratio of Eu to Ba is Ba:Eu=0.90:0.10.

-   Ba₃N₂:5.18 g-   Si₃N₄:1.97 g-   SiO₂:2.18 g-   Eu₂O₃:0.69 g

Said raw materials were mixed and calcination was carried out under thesame conditions as Example 83.

Example 86 changes the compounding ratio of Eu. Example 86 is theoxynitride phosphor in which the portion of Ba was substituted with Eu.The under-mentioned amounts of crushed powders were weighed. Wherein amolar ratio of Eu to Ba is Ba:Eu=0.85:0.15.

-   Ba₃N₂:4.87 g-   Si₃N₄:2.03 g-   SiO₂:2.09 g-   Eu₂O₃:1.03 g

Said raw materials were mixed and calcination was carried out under thesame conditions as Example 83.

Example 87 changes the compounding ratio of Eu. Example 87 is theoxynitride phosphor in which the portion of Ba was substituted with Eu.The under-mentioned amounts of crushed powders were weighed. Wherein amolar ratio of Eu to Ba is Ba:Eu=0.80:0.20.

-   Ba₃N₂:4.57 g-   Si₃N₄:2.10 g-   SiO₂:1.99 g-   Eu₂O₃:1.37 g

Said raw materials were mixed and calcination was carried out under thesame conditions as Example 83.

Any of the calcined products of Examples 83 to 87 is crystalline powderor particles. The particle diameter was about 1 to 5 μm.

Table 10 shows the luminescence properties when the oxynitride phosphorsof Examples 83 to 87 were excited by Ex=400 nm.

TABLE 10 Eu Luminescence Quantum Luminescence peak concentrationbrightness efficiency wavelength (mol) Color tone x Color tone y (%) (%)(nm) Example 83 0.03 0.106 0.471 100.0 100.0 496 Example 84 0.05 0.1210.481 85.5 83.9 498 Example 85 0.10 0.247 0.477 45.2 40.1 500 Example 860.15 0.289 0.556 33.4 22.8 504 Example 87 0.20 0.317 0.599 23.0 13.7 536

The measurement of the excitation spectra of the oxynitride phosphors ofExamples 83 to 87 was carried out. As a result of the measurement,Examples 83 to 86 are more strongly excited at from 370 nm to 470 nmthan nearby 350 nm.

The measurement of the reflection spectra of the oxynitride phosphors ofExamples 83 to 87 was carried out. As a result of the measurement,Examples 83 to 87 exhibit high absorption rate at from 290 nm to 470 nm.Accordingly, they absorb efficiently light from the excitation lightsource from 290 nm to 470 nm and can carry out wavelength conversion.

Light nearby Ex=400 nm as the excitation light source was irradiated tothe oxynitride phosphors of Examples 83 to 87 to be excited. Theoxynitride phosphor of Example 83 has a luminescence color at a greenregion of the color tone, x=0.106 and the color tone y=0.471, and theluminescence peak wavelength λp=496 nm. The oxynitride phosphor ofExample 84 has a luminescence color at a green region of the color tone,x=0.121 and the color tone y=0.481, and λp=498 nm. The oxynitridephosphor of Example 85 has a luminescence color at a green region of thecolor tone, x=0.247 and the color tone y=0.477, and λp=500 nm. Any ofthe oxynitride phosphors of Examples 83 to 85 exhibited higherluminescence efficiency than a conventional phosphor. In particular, theoxynitride phosphors of Examples 83 to 86 exhibited higher luminescenceefficiency than Example 87. Further, Examples 84 to 87 are representedby the relative value on the basis that the luminescence brightness andquantum efficiency of Example 83 is 100%.

Table 11 shows the temperature properties of the oxynitride phosphor ofExample 83. The temperature properties are shown by the relativebrightness on the basis that the luminescence brightness at 25° C. is100%. The excitation light source is light nearby Ex=400 nm.

TABLE 11 Luminescence Quantum Temperature brightness efficiency (° C.)(%) (%) 25 100.0 100.0 50 97.0 97.4 100 88.8 90.2 150 79.2 81.7 200 64.768.2

As a result, when the oxynitride phosphor was raised to 100° C., it was88.8% and keeps extremely high luminescence brightness, and even if thetemperature was further raised to 200° C., it is 64.7% and keepsextremely high luminescence brightness. The oxynitride phosphor exhibitsextremely good temperature properties.

When the X-ray diffraction images of the above-mentioned theseoxynitride phosphors were measured, any image shows a sharp diffractionpeak, and it was cleared that the phosphors obtained were crystallinecompounds having regularity.

Example 88 Light-Emitting Device

The light-emitting device of Example 88 was produced using theabove-mentioned oxynitride phosphor. As the excitation light source, alight-emitting element having a luminescence spectrum of 400 nm. As thephosphor, it is constituted in like manner as Example 28 except forusing BaSi₂O₂N₂:Eu of Example 83, (Y, Gd)₃(Al, Ga)₅O₁₂:Ce, SrCaSi₅N₈:Euand (Ca_(0.93), Eu_(0.50), Mn_(0.02))₁₀(PO₄)₆Cl₂ are used.

FIG. 68 is a chart showing the luminescence spectrum (simulation) of thelight-emitting device of Example 88. FIG. 69 is a chart showing thechromaticity coordinates (simulation) of the light-emitting devices ofExamples 88 to 90. Said light-emitting device of Example 88 adjusts acolor temperature at 4000 to 5000K.

BaSi₂O₂N₂:Eu of Example 83, (Ca_(0.93), Eu_(0.05),Mn_(0.02))₁₀(PO₄)₆Cl₂, (Y, Gd)₃(Al, Ga)₅O₁₂:Ce and SrCaSi₅N₈:Eu are usedfor the light-emitting devices of Examples 88, but the compounding ratiocan be appropriately varied. These phosphors are irradiated using theexcitation light source of Ex=400 nm. These phosphors absorb light fromthe excitation light source, carry out wavelength conversion, and have afixed luminescence wavelength. BaSi₂O₂N₂:Eu of Example 83 has theluminescence peak wavelength at 470 nm to 530 nm. (Ca_(0.93), Eu_(0.05),Mn_(0.02))₁₀(PO₄)₆Cl₂ has the luminescence peak wavelength at 440 to 500nm. (Y, Gd)₃(Al, Ga)₅O₁₂:Ce has the luminescence peak wavelength at 500to 650 nm. SrCaSi₅N₈:Eu has the luminescence peak wavelength at 580 nmto 730 nm.

Table 12 shows the properties and color rendering of the light-emittingdevice of Example 88. However, the properties and color rendering of thelight-emitting device of Example 88 are simulation, and when thelight-emitting device is practically produced, it is considered thatself absorption occurs and the deviation of wavelength is generated. Asthe light-emitting device of Comparative Example 1, the excitation lightsource of Ex=400 nm is used and (Ca_(0.93), Eu_(0.05),Mn_(0.02))₁₀(PO₄)₆Cl₂ and (Y, Gd)₃(Al, Ga)₅O₁₂:Ce are used.

TABLE 12 Luminescence properties (Ex = 400 nm) Visual sensitivity Colortone x Color tone y Color temperature (K) efficiency (%) Light emitting0.356 0.371 4693 100 device of Comparative Example 1 Light emitting0.363 0.365 4449 81.5 device of Example 88 Average color rendering indexSpecific color rendering index Ra R1 R2 R3 R4 R5 R6 R7 Light emitting76.0 74.7 90.9 92.8 60.2 69.9 82.0 78.9 device of Comparative Example 1Light emitting 88.2 94.6 89.3 84.6 85.9 92.0 86.2 84.8 device of Example88 Specific color rendering index R8 R9 R10 R11 R12 R13 R14 R15 Lightemitting 58.3 −1.9 71.8 52.2 41.9 79.8 96.4 70.1 device of ComparativeExample 1 Light emitting 88.1 96.1 75.7 89.9 75.3 92.4 91.3 92.4 deviceof Example 88

The phosphors excited by the light-emitting element at 400 nm excitationhave respectively the luminescence peak wavelengths at a blue green togreen region in case of BaSi₂O₂N₂:Eu of Example 83, at a blue purple toblue region in case (Ca_(0.93), Eu_(0.05), Mn_(0.02))₁₀(PO₄)₆Cl₂, at agreen to yellow red region in case of (Y, Gd)₃(Al, Ga)₅O₁₂:Ce and at ayellow red to red region in case of SrCaSi₅N₈:Eu. It exhibits aluminescence color at a white region by the color mixture of lights fromthese phosphors. The light-emitting device of Example 88 exhibits aluminescence color at a white region. Further, since the excitationlight source nearby 400 nm having low visual sensitivity property isused, the color tone can be easily changed by changing the compoundingratio of the phosphors. In particular, the average color rendering index(Ra) was 76.0 for a white light-emitting device which was shown inComparative Example 1, but the average color rendering index (Ra) was88.1 for the white light-emitting device related to Example 88, whichwas extremely good. Color rendering is improved thereby. Further, thecolor rendering is improved at almost all of color chips with respect tothe specific color rendering index (R1 to R15). Furthermore, thespecific color rendering index (R9) is −1.9 for a white light-emittingdevice which was shown in Comparative Example 1, but the specific colorrendering index (R9) is 96.1 for the white light-emitting device relatedto Example 88, which was extremely good. The specific color renderingindex (R9) is a red color chip having comparatively high chroma. Visualsensitivity efficiency is represented by a relative value when the whitelight-emitting device of Comparative Example 1 was 100%.

Examples 89 and 90 Light-Emitting Device

The light-emitting devices of Examples 89 and 90 relate to a whitelight-emitting device using a light-emitting element having aluminescence spectrum of 460 nm the excitation light source. Thelight-emitting devices of Examples 89 and 90 are constituted in likemanner as Example 29 except for using phosphors below as the phosphor 11in the light-emitting devices of Example 29 (the basic constitution isFIG. 1). FIG. 70 is a chart showing the luminescence spectra(simulation) of the light-emitting devices of Examples 89 and 90.

(Phosphors in Light-Emitting Devices of Examples 89 and 90)

The phosphor 11 used in the light-emitting devices of Example 89 and 90related to the present invention is a phosphor mixing the oxynitridephosphor of Example 83, a YAG phosphor represented by (Y, Gd)₃(Al,Ga)₅O₁₂:Ce, and a nitride phosphor represented by CaSrSi₅N₈:Eu. Saidphosphor 11 is mixed together with the coating member 12. Thecompounding ratio can be varied. These phosphors are irradiated usingthe excitation light source of Ex=460 nm. These phosphors 11 absorblight from said excitation light source, carry out the wavelengthconversion, and have a fixed luminescence wavelength. The BaSi₂O₂N₂:Euof Example 83 has the luminescence peak wavelength at 470 nm to 530 nm.(Y, Gd)₃(Al, Ga)₅O₁₂:Ce has the luminescence peak wavelength at 500 to650 nm. SrCaSi₅N₈:Eu has the luminescence peak wavelength at 580 nm to730 nm.

When current is run in the light-emitting devices of Examples 89 and 90,the blue light-emitting element 10 having the luminescence peakwavelength nearby 460 nm emits light. The portion of the light of thelight-emitting element 10 transmits in the light-emitting devices ofExamples 89 and 90. Further, the portion of the light of thelight-emitting element 10 excites the phosphor 11, carries out thewavelength conversion, and said phosphor 11 have a fixed luminescencewavelength. There can be provided the light-emitting device which emitswhite light, by the color mixture of the blue light from theselight-emitting element 10 and the light from the phosphor 11.

Namely, the phosphors 11 which covers the semiconductor layer convertthe color tone of the portion of blue light from the light-emittingelements. As a result, the light-emitting devices of Examples 89 and 90which emit white light can be provided.

(Properties of Light-Emitting Devices of Examples 89 and 90)

Table 13 shows the properties and color rendering of the light-emittingdevices of Examples 89 and 90. However, the properties and colorrendering of the light-emitting devices of Examples 89 and 90 aresimulation, and when the light-emitting device is practically produced,it is considered that self absorption occurs and the deviation ofwavelength is generated. As the light-emitting device of ComparativeExample 2, the excitation light source of Ex=460 nm is used and (Y,Gd)₃(Al, Ga)₅O₁₂:Ce is used. Further, Examples 89 and 90 are theluminescence spectrum when the peak values are the same.

TABLE 13 Luminescence properties (Ex = 460 nm) Color Color Color Visualsensitivity tone x tone y temperature (K) efficiency (%) Light 0.3560.371 4693 100 emitting device of Comparative Example 2 Light 0.3520.358 4773 86.1 emitting device of Example 89 Light 0.356 0.360 464381.8 emitting device of Example 90 Average color rendering indexSpecific color rendering index Ra R1 R2 R3 R4 R5 R6 R7 Light 76.0 74.790.9 92.8 60.2 69.9 82.0 78.9 emitting device of Com- parative Example 2Light 84.5 93.9 92.3 85.2 72.4 86.5 91.3 77.5 emitting device of Example89 Light 83.1 93.5 86.0 79.9 96.0 88.0 83.2 96.6 emitting device ofExample 90 Specific color rendering index R8 R9 R10 R11 R12 R13 R14 R15Light 58.3 −1.9 71.8 52.2 41.9 79.8 96.4 70.1 emitting device ofComparative Example 2 Light 77.1 70.7 87.0 73.8 63.1 97.9 92.4 88.0emitting device of Example 89 Light 81.5 94.1 70.5 81.3 65.0 90.8 89.288.3 emitting device of Example 90

The luminescence spectra of the phosphors excited by light of 460 nmfrom the light-emitting element have respectively the luminescence peakwavelengths at a blue green to green region in case of BaSi₂O₂N₂:Eu ofExample 83, at a green to yellow red region in case of (Y, Gd)₃(Al,Ga)₅O₁₂:Ce and at a yellow red to red region in case of SrCaSi₅N₈:Eu. Itexhibits a luminescence color at a white region by the color mixture oflights from these phosphors. The light-emitting devices of Examples 89and 90 exhibit a luminescence color at a white region as a whole.Further, since visual light nearby 460 nm as the excitation light sourceis used and the phosphor emitting blue light is not used, there islittle loss of luminescence efficiency in accordance with the wavelengthconversion. Further, the color tone can be easily changed by changingthe compounding ratio of the phosphors. In particular, the average colorrendering index (Ra) was 76.0 for a white light-emitting device whichwas shown in Comparative Example 2, but the average color renderingindices (Ra) were 84.5 and 83.1 for the white light-emitting devicesrelated to Examples 89 and 90, which was extremely good. Color renderingis improved thereby. Further, the color rendering is improved at almostall of color chips with respect to the specific color rendering index(R1 to R15). Furthermore, the specific color rendering index (R9) is−1.9 for a white light-emitting device which was shown in ComparativeExample 2, but the specific color rendering indices (R9) are 70.7 and94.1 for the white light-emitting devices related to Examples 89 and 90,which were extremely good. The specific color rendering indices (R9) area red color chip having comparatively high chroma. Visual sensitivityefficiency is represented by a relative value when the whitelight-emitting device of Comparative Example was 100%.

Example 91 Light-Emitting Device

The light-emitting device of Example 91 relates to a whitelight-emitting device using a light-emitting element having theluminescence peak wavelength at 457 nm, as an excitation light source.The basic structure is the structure shown in FIG. 1. FIG. 71 is a chartshowing the luminescence spectra of the light-emitting devices ofExamples 91 and 92.

(Light-Emitting Element)

When current is run in the light-emitting device of Example 91, the bluelight-emitting element 10 having a peak wave length at about 457 nmemits light. The phosphor 11 which covers the semiconductor layer 2carries out the conversion of color tone. As a result, there can beprovided the light-emitting device of Example 91 which emits whitelight.

(Phosphor)

The phosphor 11 used for the light-emitting device of Example 91 relatedto the present invention uses the phosphors 11 which mixed theoxynitride phosphor of Example 83, the YAG phosphor represented by (Y,Gd)₃(Al, Ga)₅O₁₂:Ce and the nitride phosphor represented bySrCaSi₅N₈:Eu. Said phosphor 11 is mixed with the coating member 12. Thecompounding ratio can be appropriately changed. These phosphors 11 areirradiated using the excitation light source of Ex=457 nm. Thesephosphors 11 absorb light from said excitation light source, carry outthe wavelength conversion, and have a fixed wavelength. BaSi₂O₂N₂:Eu ofExample 83 has the luminescence peak wavelength at 470 nm to 530 nm. (Y,Gd)₃(Al, Ga)₅O₁₂:Ce has the luminescence peak wavelength at 500 to 650nm. SrCaSi₅N₈:Eu has the luminescence peak wavelength at 580 nm to 730nm.

The portion of light of the light-emitting element 10 transmits thelight-emitting device of Example 91. Further, the portion of the lightof the light-emitting element 10 excites the phosphors 11 and carriesout the wavelength conversion, and said phosphors 11 have a fixedluminescence wavelength. There can be provided the light-emitting devicewhich emits white light, by the color mixture of the blue light fromthese light-emitting elements 10 and the light from the phosphors 11.

(Properties of Light-Emitting Device of Example 91)

Table 14 shows the properties and color rendering of the light-emittingdevice of Example 91.

TABLE 14 Luminescence properties (Ex = 457 nm) Luminescence Radiationpeak Color Lamp Current Voltage analysis Brightness wavelength ColorColor temperature efficiency If (mA) Vf (V) (mW) (beam) (lm) (nm) tone xtone y (K) (lm/W) Light 20 3.38 6.3 1.69 453 0.334 0.340 5443 25.0emitting device of Example 91 Average color rendering index Specificcolor rendering index Ra R1 R2 R3 R4 R5 R6 R7 Light 92.7 96.6 94.8 90.593.8 95.7 91.6 89.8 emitting device of Example 91 Specific colorrendering index R8 R9 R10 R11 R12 R13 R14 Light 89.0 83.0 88.7 96.4 81.096.8 94.4 emitting device of Example 91

The phosphors excited by the light-emitting element of 457 nm excitationhave respectively the luminescence peak wavelengths at a blue green togreen region in case of BaSi₂O₂N₂:Eu of Example 83, at a green to yellowred region in case of (Y, Gd)₃(Al, Ga)₅O₁₂:Ce and at a yellow red to redregion in case of SrCaSi₅N₈:Eu. The light-emitting device of Example 91exhibits a luminescence color at a white region by the color mixture oflights from these phosphors. Further, since visual light nearby 457 nmas the excitation light source is used and the phosphor emitting bluelight is not used, there is little loss of luminescence efficiencyaccompanied with the wavelength conversion. Further, the color tone canbe easily changed by changing the compounding ratio of the phosphors.The white light-emitting device of Example 91 exhibits extremely highluminescence efficiency in which lamp efficiency is 25.01 m/W. Theaverage color rendering index (Ra) was 92.7 for the white light-emittingdevice related to Example 91, which was extremely good. Color renderingis improved thereby. Further, the color rendering is improved at almostall of color chips with respect to the specific color rendering index(R1 to R15). Furthermore, the specific color rendering index (R9) is83.0 for the white light-emitting device related to Example 91, whichwas extremely good.

Therefore, the white light-emitting device of Example 91 can provide alight-emitting device with superior color rendering.

Example 92 Light-Emitting Device

The light-emitting device of Example 92 relates to a whitelight-emitting device using a light-emitting element having theluminescence peak wavelength at 463 nm, as an excitation light source.The basic structure is the structure shown in FIG. 1. FIG. 71 is a chartshowing the luminescence spectra of the light-emitting devices ofExamples 91 and 92.

(Light-Emitting Element)

When current is run in the light-emitting device of Example 92, the bluelight-emitting element 10 having a peak wave length at about 463 nmemits light. The phosphor 11 which covers the semiconductor layer 2converts the color tone of the blue light. As a result, there can beprovided the light-emitting device of Example 92 which emits whitelight.

(Phosphor)

The phosphor 11 used for the light-emitting device of Example 92 usesthe phosphors 11 which mixed the oxynitride phosphor of Example 83, theYAG phosphor represented by (Y, Gd)₃(Al, Ga)₅O₁₂:Ce and the nitridephosphor represented by CaSrSi₅N₈:Eu. Said phosphors 11 are mixed withthe coating member 12. The compounding ratio can be appropriatelychanged. These phosphors 11 are irradiated using the excitation lightsource of Ex=463 nm. These phosphors 11 absorb light from saidexcitation light source, carry out the wavelength conversion, and have afixed wavelength. BaSi₂O₂N₂:Eu of Example 83 has the luminescence peakwavelength at 470 nm to 530 nm. (Y, Gd)₃(Al, Ga)₅O₁₂:Ce has theluminescence peak wavelength at 500 nm to 650 nm. SrCaSi₅N₈:Eu has theluminescence peak wavelength at 580 to 730 nm.

The portion of light of the light-emitting element 10 transmits thelight-emitting device of Example 92. Further, the portion of the lightof the light-emitting element 10 excites the phosphors 11 and carriesout the wavelength conversion, and said phosphors 11 have a fixedluminescence wavelength. There can be provided the light-emitting devicewhich emits white light, by the color mixture of the blue light fromthese light-emitting elements 10 and the light from the phosphors 11.

(Properties of Light-Emitting Device of Example 92)

Table 15 shows the properties and color rendering of the light-emittingdevice of Example 92.

TABLE 15 Luminescence properties (Ex = 463 nm) Luminescence Radiationpeak Color Lamp Current Voltage analysis Brightness wavelength ColorColor temperature efficiency If (mA) Vf (V) (mW) (beam) (lm) (nm) tone xtone y (K) (lm/W) Light 20 3.28 5.4 1.397 460 0.327 0.334 5751 21.3emitting device of Example 92 Average color rendering index Specificcolor rendering index Ra R1 R2 R3 R4 R5 R6 R7 Light 84.9 90.9 86.3 81.683.2 88.1 82.2 81.4 emitting device of Example 92 Specific colorrendering index R8 R9 R10 R11 R12 R13 R14 Light 85.8 91.0 69.9 88.0 70.788.9 89.6 emitting device of Example 92

The phosphors excited by the light-emitting element of 463 nm excitationhave respectively the luminescence peak wavelengths at a blue green togreen region in case of BaSi₂O₂N₂:Eu of Example 83, at a green to yellowred region in case of (Y, Gd)₃(Al, Ga)₅O₁₂:Ce and at a yellow red to redregion in case of SrCaSi₅N₈:Eu. The light-emitting device of Example 92exhibits a luminescence color at a white region by the color mixture oflights from these phosphors. Thus, the light-emitting device of Example92 exhibits a luminescence color at a white region. Further, sincevisual light nearby 463 nm as the excitation light source is used andthe phosphor emitting blue light is not used, there is little loss ofluminescence efficiency accompanied with the wavelength conversion.Further, the color tone can be easily changed by changing thecompounding ratio of the phosphors. The white light-emitting device ofExample 92 exhibits extremely high luminescence properties in which lampefficiency is 21.31 m/W. The average color rendering index (Ra) was 84.9for the white light-emitting device related to Example 92, which wasextremely good. Color rendering is improved thereby. Further, the colorrendering is improved at almost all of color chips with respect to thespecific color rendering index (R1 to R15). Furthermore, the specificcolor rendering index (R9) is 91.0 for the white color light-emittingdevice related to Example 92, which was extremely good.

The white color light-emitting device of Example 92 can provide alight-emitting device with superior color rendering, thereby.

Example 93 Light-Emitting Device

The light-emitting device of Example 93 is a cap type light-emittingdevice in like manner as the light-emitting device of Example 30, and isconstituted in like manner as Example 30 except for setting the phosphor11 as below in the light-emitting device of Example 30. Further, as thelight-emitting element 10, a light-emitting element having theluminescence peak wavelength at 400 nm is used.

The phosphor of (Y, Gd)₃(Al, Ga)₅O₁₂:Ce, the nitride phosphor ofBa₂Si₅N₈:Eu and the phosphor of BaSi₂O₂N₂:Eu are contained in the cap16. The phosphor of (Ca_(0.95), Eu_(0.05))₁₀(PO₄)₆Cl₂ is contained inthe coating member 12 in the cup of the mount lead 13 a. Further, sincethe phosphors can be contained in the cap 16, the cap 16 may contain theoxynitride phosphor and only the coating member 12 exists in the cup ofthe mount lead 13 a.

In the light-emitting device thus constituted, the portion of lightreleased from the light-emitting element 10 excites the oxynitridephosphor of the phosphor 11 and green light is emitted. Further, theportion of light emitted from the light-emitting element 10 or theportion of light emitted from the oxynitride phosphor excites thephosphors of the cap 16, and red light is emitted from blue and yellow.The green light of the oxynitride phosphor is mixed with the red lightfrom the blue color and yellow color of the phosphor of the cap 16thereby, and as a result, white light is externally released from thesurface of the cap 16.

INDUSTRIAL APPLICABILITY

As specifically illustrated above, the present invention relates to anoxynitride phosphor which absorbs light from an excitation light sourcehaving a luminescence wavelength at an ultraviolet to visible lightregion and has a luminescence color different from the luminescencecolor from said excitation light source; and said oxynitride phosphorhas a luminescence peak wavelength at a blue green to yellow region andextremely high luminescence efficiency. Further, said oxynitridephosphor is extremely superior in temperature properties. Further, thepresent invention is a production process by which the oxynitridephosphor can be simply produced in good reproducibility. Furthermore,the present invention relates to a light-emitting device having theabove-mentioned oxynitride phosphor and a light-emitting element, andsaid light-emitting device can realize a desired luminescence color.Furthermore, there can be produced a light-emitting device combining theabove-mentioned oxynitride phosphor with a phosphor being the secondphosphor which emits light with a blue color, green color, red color,yellow color and the like. A light-emitting device superior in colorrendering which emits white light can be provided thereby. Further,there can be produced a light-emitting device combining said oxynitridephosphor, a YAG phosphor being the second phosphor and a bluelight-emitting element. A light-emitting device superior in colorrendering and having extremely high luminescence efficiency which emitswhite light can be provided thereby. Accordingly, the present inventionhas an extremely important meaning that the above-mentionedlight-emitting devices can be provided.

1. An oxynitride phosphor consisting of a crystal which has a unitlattice of the rhombic system, the oxynitride phosphor being representedby a general formula of SrxSiyOzN_(((2/3)X+(4/3)Y−(2/3)Z)):R (R is arare earth element. 0.5<X<1.5, 1.5<Y<2.5, and 1.5<Z<2.5), wherein saidSr and said activator R are in a molar ratio of 1:0.22 to 1:0.7.
 2. Theoxynitride phosphor according to claim 1, wherein said crystal issubstantially Al-free crystal.
 3. The oxynitride phosphor according toclaim 1, containing O and N of which weight ratio is set so that N iswithin a range of 0.2 to 2.1 per 1 of O.
 4. The oxynitride phosphoraccording to claim 1, wherein said activator R contains Eu.
 5. Theoxynitride phosphor according to claim 4, wherein said X, said Y andsaid Z are X=1, Y=2, and Z=2.
 6. The oxynitride phosphor according toclaim 1, which is excited by light from an excitation light sourcehaving a luminescence peak wavelength at 490 nm or less, and haveluminescence spectra having luminescence peak wavelengths at a longerwavelength side than said luminescence peak wavelength.
 7. Theoxynitride phosphor according to claim 1, which has a luminescencespectra having a peak wavelength in a range of from blue green toyellow.
 8. The oxynitride phosphor according to claim 1, whereinluminescence intensity excited by light of 370 nm is higher thanluminescence intensity excited by light of 500 nm.